// hashtable.h header -*- C++ -*- // Copyright (C) 2007-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/hashtable.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{unordered_map, unordered_set} */ #ifndef _HASHTABLE_H #define _HASHTABLE_H 1 #pragma GCC system_header #include <bits/hashtable_policy.h> #if __cplusplus > 201402L # include <bits/node_handle.h> #endif namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Tp, typename _Hash> using __cache_default = __not_<__and_<// Do not cache for fast hasher. __is_fast_hash<_Hash>, // Mandatory to have erase not throwing. __is_nothrow_invocable<const _Hash&, const _Tp&>>>; /** * Primary class template _Hashtable. * * @ingroup hashtable-detail * * @tparam _Value CopyConstructible type. * * @tparam _Key CopyConstructible type. * * @tparam _Alloc An allocator type * ([lib.allocator.requirements]) whose _Alloc::value_type is * _Value. As a conforming extension, we allow for * _Alloc::value_type != _Value. * * @tparam _ExtractKey Function object that takes an object of type * _Value and returns a value of type _Key. * * @tparam _Equal Function object that takes two objects of type k * and returns a bool-like value that is true if the two objects * are considered equal. * * @tparam _H1 The hash function. A unary function object with * argument type _Key and result type size_t. Return values should * be distributed over the entire range [0, numeric_limits<size_t>:::max()]. * * @tparam _H2 The range-hashing function (in the terminology of * Tavori and Dreizin). A binary function object whose argument * types and result type are all size_t. Given arguments r and N, * the return value is in the range [0, N). * * @tparam _Hash The ranged hash function (Tavori and Dreizin). A * binary function whose argument types are _Key and size_t and * whose result type is size_t. Given arguments k and N, the * return value is in the range [0, N). Default: hash(k, N) = * h2(h1(k), N). If _Hash is anything other than the default, _H1 * and _H2 are ignored. * * @tparam _RehashPolicy Policy class with three members, all of * which govern the bucket count. _M_next_bkt(n) returns a bucket * count no smaller than n. _M_bkt_for_elements(n) returns a * bucket count appropriate for an element count of n. * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the * current bucket count is n_bkt and the current element count is * n_elt, we need to increase the bucket count. If so, returns * make_pair(true, n), where n is the new bucket count. If not, * returns make_pair(false, <anything>) * * @tparam _Traits Compile-time class with three boolean * std::integral_constant members: __cache_hash_code, __constant_iterators, * __unique_keys. * * Each _Hashtable data structure has: * * - _Bucket[] _M_buckets * - _Hash_node_base _M_before_begin * - size_type _M_bucket_count * - size_type _M_element_count * * with _Bucket being _Hash_node* and _Hash_node containing: * * - _Hash_node* _M_next * - Tp _M_value * - size_t _M_hash_code if cache_hash_code is true * * In terms of Standard containers the hashtable is like the aggregation of: * * - std::forward_list<_Node> containing the elements * - std::vector<std::forward_list<_Node>::iterator> representing the buckets * * The non-empty buckets contain the node before the first node in the * bucket. This design makes it possible to implement something like a * std::forward_list::insert_after on container insertion and * std::forward_list::erase_after on container erase * calls. _M_before_begin is equivalent to * std::forward_list::before_begin. Empty buckets contain * nullptr. Note that one of the non-empty buckets contains * &_M_before_begin which is not a dereferenceable node so the * node pointer in a bucket shall never be dereferenced, only its * next node can be. * * Walking through a bucket's nodes requires a check on the hash code to * see if each node is still in the bucket. Such a design assumes a * quite efficient hash functor and is one of the reasons it is * highly advisable to set __cache_hash_code to true. * * The container iterators are simply built from nodes. This way * incrementing the iterator is perfectly efficient independent of * how many empty buckets there are in the container. * * On insert we compute the element's hash code and use it to find the * bucket index. If the element must be inserted in an empty bucket * we add it at the beginning of the singly linked list and make the * bucket point to _M_before_begin. The bucket that used to point to * _M_before_begin, if any, is updated to point to its new before * begin node. * * On erase, the simple iterator design requires using the hash * functor to get the index of the bucket to update. For this * reason, when __cache_hash_code is set to false the hash functor must * not throw and this is enforced by a static assertion. * * Functionality is implemented by decomposition into base classes, * where the derived _Hashtable class is used in _Map_base, * _Insert, _Rehash_base, and _Equality base classes to access the * "this" pointer. _Hashtable_base is used in the base classes as a * non-recursive, fully-completed-type so that detailed nested type * information, such as iterator type and node type, can be * used. This is similar to the "Curiously Recurring Template * Pattern" (CRTP) technique, but uses a reconstructed, not * explicitly passed, template pattern. * * Base class templates are: * - __detail::_Hashtable_base * - __detail::_Map_base * - __detail::_Insert * - __detail::_Rehash_base * - __detail::_Equality */ template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> class _Hashtable : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>, public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>, public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>, public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>, public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>, private __detail::_Hashtable_alloc< __alloc_rebind<_Alloc, __detail::_Hash_node<_Value, _Traits::__hash_cached::value>>> { static_assert(is_same<typename remove_cv<_Value>::type, _Value>::value, "unordered container must have a non-const, non-volatile value_type"); #if __cplusplus > 201703L || defined __STRICT_ANSI__ static_assert(is_same<typename _Alloc::value_type, _Value>{}, "unordered container must have the same value_type as its allocator"); #endif using __traits_type = _Traits; using __hash_cached = typename __traits_type::__hash_cached; using __node_type = __detail::_Hash_node<_Value, __hash_cached::value>; using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>; using __hashtable_alloc = __detail::_Hashtable_alloc<__node_alloc_type>; using __value_alloc_traits = typename __hashtable_alloc::__value_alloc_traits; using __node_alloc_traits = typename __hashtable_alloc::__node_alloc_traits; using __node_base = typename __hashtable_alloc::__node_base; using __bucket_type = typename __hashtable_alloc::__bucket_type; public: typedef _Key key_type; typedef _Value value_type; typedef _Alloc allocator_type; typedef _Equal key_equal; // mapped_type, if present, comes from _Map_base. // hasher, if present, comes from _Hash_code_base/_Hashtable_base. typedef typename __value_alloc_traits::pointer pointer; typedef typename __value_alloc_traits::const_pointer const_pointer; typedef value_type& reference; typedef const value_type& const_reference; private: using __rehash_type = _RehashPolicy; using __rehash_state = typename __rehash_type::_State; using __constant_iterators = typename __traits_type::__constant_iterators; using __unique_keys = typename __traits_type::__unique_keys; using __key_extract = typename std::conditional< __constant_iterators::value, __detail::_Identity, __detail::_Select1st>::type; using __hashtable_base = __detail:: _Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>; using __hash_code_base = typename __hashtable_base::__hash_code_base; using __hash_code = typename __hashtable_base::__hash_code; using __ireturn_type = typename __hashtable_base::__ireturn_type; using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using __reuse_or_alloc_node_gen_t = __detail::_ReuseOrAllocNode<__node_alloc_type>; using __alloc_node_gen_t = __detail::_AllocNode<__node_alloc_type>; // Simple RAII type for managing a node containing an element struct _Scoped_node { // Take ownership of a node with a constructed element. _Scoped_node(__node_type* __n, __hashtable_alloc* __h) : _M_h(__h), _M_node(__n) { } // Allocate a node and construct an element within it. template<typename... _Args> _Scoped_node(__hashtable_alloc* __h, _Args&&... __args) : _M_h(__h), _M_node(__h->_M_allocate_node(std::forward<_Args>(__args)...)) { } // Destroy element and deallocate node. ~_Scoped_node() { if (_M_node) _M_h->_M_deallocate_node(_M_node); }; _Scoped_node(const _Scoped_node&) = delete; _Scoped_node& operator=(const _Scoped_node&) = delete; __hashtable_alloc* _M_h; __node_type* _M_node; }; template<typename _Ht> static constexpr typename conditional<std::is_lvalue_reference<_Ht>::value, const value_type&, value_type&&>::type __fwd_value_for(value_type& __val) noexcept { return std::move(__val); } // Metaprogramming for picking apart hash caching. template<typename _Cond> using __if_hash_cached = __or_<__not_<__hash_cached>, _Cond>; template<typename _Cond> using __if_hash_not_cached = __or_<__hash_cached, _Cond>; // Compile-time diagnostics. // _Hash_code_base has everything protected, so use this derived type to // access it. struct __hash_code_base_access : __hash_code_base { using __hash_code_base::_M_bucket_index; }; // Getting a bucket index from a node shall not throw because it is used // in methods (erase, swap...) that shall not throw. static_assert(noexcept(declval<const __hash_code_base_access&>() ._M_bucket_index((const __node_type*)nullptr, (std::size_t)0)), "Cache the hash code or qualify your functors involved" " in hash code and bucket index computation with noexcept"); // When hash codes are cached local iterator inherits from H2 functor // which must then be default constructible. static_assert(__if_hash_cached<is_default_constructible<_H2>>::value, "Functor used to map hash code to bucket index" " must be default constructible"); template<typename _Keya, typename _Valuea, typename _Alloca, typename _ExtractKeya, typename _Equala, typename _H1a, typename _H2a, typename _Hasha, typename _RehashPolicya, typename _Traitsa, bool _Unique_keysa> friend struct __detail::_Map_base; template<typename _Keya, typename _Valuea, typename _Alloca, typename _ExtractKeya, typename _Equala, typename _H1a, typename _H2a, typename _Hasha, typename _RehashPolicya, typename _Traitsa> friend struct __detail::_Insert_base; template<typename _Keya, typename _Valuea, typename _Alloca, typename _ExtractKeya, typename _Equala, typename _H1a, typename _H2a, typename _Hasha, typename _RehashPolicya, typename _Traitsa, bool _Constant_iteratorsa> friend struct __detail::_Insert; template<typename _Keya, typename _Valuea, typename _Alloca, typename _ExtractKeya, typename _Equala, typename _H1a, typename _H2a, typename _Hasha, typename _RehashPolicya, typename _Traitsa, bool _Unique_keysa> friend struct __detail::_Equality; public: using size_type = typename __hashtable_base::size_type; using difference_type = typename __hashtable_base::difference_type; using iterator = typename __hashtable_base::iterator; using const_iterator = typename __hashtable_base::const_iterator; using local_iterator = typename __hashtable_base::local_iterator; using const_local_iterator = typename __hashtable_base:: const_local_iterator; #if __cplusplus > 201402L using node_type = _Node_handle<_Key, _Value, __node_alloc_type>; using insert_return_type = _Node_insert_return<iterator, node_type>; #endif private: __bucket_type* _M_buckets = &_M_single_bucket; size_type _M_bucket_count = 1; __node_base _M_before_begin; size_type _M_element_count = 0; _RehashPolicy _M_rehash_policy; // A single bucket used when only need for 1 bucket. Especially // interesting in move semantic to leave hashtable with only 1 bucket // which is not allocated so that we can have those operations noexcept // qualified. // Note that we can't leave hashtable with 0 bucket without adding // numerous checks in the code to avoid 0 modulus. __bucket_type _M_single_bucket = nullptr; bool _M_uses_single_bucket(__bucket_type* __bkts) const { return __builtin_expect(__bkts == &_M_single_bucket, false); } bool _M_uses_single_bucket() const { return _M_uses_single_bucket(_M_buckets); } __hashtable_alloc& _M_base_alloc() { return *this; } __bucket_type* _M_allocate_buckets(size_type __bkt_count) { if (__builtin_expect(__bkt_count == 1, false)) { _M_single_bucket = nullptr; return &_M_single_bucket; } return __hashtable_alloc::_M_allocate_buckets(__bkt_count); } void _M_deallocate_buckets(__bucket_type* __bkts, size_type __bkt_count) { if (_M_uses_single_bucket(__bkts)) return; __hashtable_alloc::_M_deallocate_buckets(__bkts, __bkt_count); } void _M_deallocate_buckets() { _M_deallocate_buckets(_M_buckets, _M_bucket_count); } // Gets bucket begin, deals with the fact that non-empty buckets contain // their before begin node. __node_type* _M_bucket_begin(size_type __bkt) const; __node_type* _M_begin() const { return static_cast<__node_type*>(_M_before_begin._M_nxt); } // Assign *this using another _Hashtable instance. Whether elements // are copied or moved depends on the _Ht reference. template<typename _Ht> void _M_assign_elements(_Ht&&); template<typename _Ht, typename _NodeGenerator> void _M_assign(_Ht&&, const _NodeGenerator&); void _M_move_assign(_Hashtable&&, true_type); void _M_move_assign(_Hashtable&&, false_type); void _M_reset() noexcept; _Hashtable(const _H1& __h1, const _H2& __h2, const _Hash& __h, const _Equal& __eq, const _ExtractKey& __exk, const allocator_type& __a) : __hashtable_base(__exk, __h1, __h2, __h, __eq), __hashtable_alloc(__node_alloc_type(__a)) { } public: // Constructor, destructor, assignment, swap _Hashtable() = default; _Hashtable(size_type __bkt_count_hint, const _H1&, const _H2&, const _Hash&, const _Equal&, const _ExtractKey&, const allocator_type&); template<typename _InputIterator> _Hashtable(_InputIterator __first, _InputIterator __last, size_type __bkt_count_hint, const _H1&, const _H2&, const _Hash&, const _Equal&, const _ExtractKey&, const allocator_type&); _Hashtable(const _Hashtable&); _Hashtable(_Hashtable&&) noexcept; _Hashtable(const _Hashtable&, const allocator_type&); _Hashtable(_Hashtable&&, const allocator_type&); // Use delegating constructors. explicit _Hashtable(const allocator_type& __a) : __hashtable_alloc(__node_alloc_type(__a)) { } explicit _Hashtable(size_type __bkt_count_hint, const _H1& __hf = _H1(), const key_equal& __eql = key_equal(), const allocator_type& __a = allocator_type()) : _Hashtable(__bkt_count_hint, __hf, _H2(), _Hash(), __eql, __key_extract(), __a) { } template<typename _InputIterator> _Hashtable(_InputIterator __f, _InputIterator __l, size_type __bkt_count_hint = 0, const _H1& __hf = _H1(), const key_equal& __eql = key_equal(), const allocator_type& __a = allocator_type()) : _Hashtable(__f, __l, __bkt_count_hint, __hf, _H2(), _Hash(), __eql, __key_extract(), __a) { } _Hashtable(initializer_list<value_type> __l, size_type __bkt_count_hint = 0, const _H1& __hf = _H1(), const key_equal& __eql = key_equal(), const allocator_type& __a = allocator_type()) : _Hashtable(__l.begin(), __l.end(), __bkt_count_hint, __hf, _H2(), _Hash(), __eql, __key_extract(), __a) { } _Hashtable& operator=(const _Hashtable& __ht); _Hashtable& operator=(_Hashtable&& __ht) noexcept(__node_alloc_traits::_S_nothrow_move() && is_nothrow_move_assignable<_H1>::value && is_nothrow_move_assignable<_Equal>::value) { constexpr bool __move_storage = __node_alloc_traits::_S_propagate_on_move_assign() || __node_alloc_traits::_S_always_equal(); _M_move_assign(std::move(__ht), __bool_constant<__move_storage>()); return *this; } _Hashtable& operator=(initializer_list<value_type> __l) { __reuse_or_alloc_node_gen_t __roan(_M_begin(), *this); _M_before_begin._M_nxt = nullptr; clear(); this->_M_insert_range(__l.begin(), __l.end(), __roan, __unique_keys()); return *this; } ~_Hashtable() noexcept; void swap(_Hashtable&) noexcept(__and_<__is_nothrow_swappable<_H1>, __is_nothrow_swappable<_Equal>>::value); // Basic container operations iterator begin() noexcept { return iterator(_M_begin()); } const_iterator begin() const noexcept { return const_iterator(_M_begin()); } iterator end() noexcept { return iterator(nullptr); } const_iterator end() const noexcept { return const_iterator(nullptr); } const_iterator cbegin() const noexcept { return const_iterator(_M_begin()); } const_iterator cend() const noexcept { return const_iterator(nullptr); } size_type size() const noexcept { return _M_element_count; } _GLIBCXX_NODISCARD bool empty() const noexcept { return size() == 0; } allocator_type get_allocator() const noexcept { return allocator_type(this->_M_node_allocator()); } size_type max_size() const noexcept { return __node_alloc_traits::max_size(this->_M_node_allocator()); } // Observers key_equal key_eq() const { return this->_M_eq(); } // hash_function, if present, comes from _Hash_code_base. // Bucket operations size_type bucket_count() const noexcept { return _M_bucket_count; } size_type max_bucket_count() const noexcept { return max_size(); } size_type bucket_size(size_type __bkt) const { return std::distance(begin(__bkt), end(__bkt)); } size_type bucket(const key_type& __k) const { return _M_bucket_index(__k, this->_M_hash_code(__k)); } local_iterator begin(size_type __bkt) { return local_iterator(*this, _M_bucket_begin(__bkt), __bkt, _M_bucket_count); } local_iterator end(size_type __bkt) { return local_iterator(*this, nullptr, __bkt, _M_bucket_count); } const_local_iterator begin(size_type __bkt) const { return const_local_iterator(*this, _M_bucket_begin(__bkt), __bkt, _M_bucket_count); } const_local_iterator end(size_type __bkt) const { return const_local_iterator(*this, nullptr, __bkt, _M_bucket_count); } // DR 691. const_local_iterator cbegin(size_type __bkt) const { return const_local_iterator(*this, _M_bucket_begin(__bkt), __bkt, _M_bucket_count); } const_local_iterator cend(size_type __bkt) const { return const_local_iterator(*this, nullptr, __bkt, _M_bucket_count); } float load_factor() const noexcept { return static_cast<float>(size()) / static_cast<float>(bucket_count()); } // max_load_factor, if present, comes from _Rehash_base. // Generalization of max_load_factor. Extension, not found in // TR1. Only useful if _RehashPolicy is something other than // the default. const _RehashPolicy& __rehash_policy() const { return _M_rehash_policy; } void __rehash_policy(const _RehashPolicy& __pol) { _M_rehash_policy = __pol; } // Lookup. iterator find(const key_type& __k); const_iterator find(const key_type& __k) const; size_type count(const key_type& __k) const; std::pair<iterator, iterator> equal_range(const key_type& __k); std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const; protected: // Bucket index computation helpers. size_type _M_bucket_index(__node_type* __n) const noexcept { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); } size_type _M_bucket_index(const key_type& __k, __hash_code __c) const { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); } // Find and insert helper functions and types // Find the node before the one matching the criteria. __node_base* _M_find_before_node(size_type, const key_type&, __hash_code) const; __node_type* _M_find_node(size_type __bkt, const key_type& __key, __hash_code __c) const { __node_base* __before_n = _M_find_before_node(__bkt, __key, __c); if (__before_n) return static_cast<__node_type*>(__before_n->_M_nxt); return nullptr; } // Insert a node at the beginning of a bucket. void _M_insert_bucket_begin(size_type, __node_type*); // Remove the bucket first node void _M_remove_bucket_begin(size_type __bkt, __node_type* __next_n, size_type __next_bkt); // Get the node before __n in the bucket __bkt __node_base* _M_get_previous_node(size_type __bkt, __node_base* __n); // Insert node __n with key __k and hash code __code, in bucket __bkt // if no rehash (assumes no element with same key already present). // Takes ownership of __n if insertion succeeds, throws otherwise. iterator _M_insert_unique_node(const key_type& __k, size_type __bkt, __hash_code __code, __node_type* __n, size_type __n_elt = 1); // Insert node __n with key __k and hash code __code. // Takes ownership of __n if insertion succeeds, throws otherwise. iterator _M_insert_multi_node(__node_type* __hint, const key_type& __k, __hash_code __code, __node_type* __n); template<typename... _Args> std::pair<iterator, bool> _M_emplace(true_type, _Args&&... __args); template<typename... _Args> iterator _M_emplace(false_type __uk, _Args&&... __args) { return _M_emplace(cend(), __uk, std::forward<_Args>(__args)...); } // Emplace with hint, useless when keys are unique. template<typename... _Args> iterator _M_emplace(const_iterator, true_type __uk, _Args&&... __args) { return _M_emplace(__uk, std::forward<_Args>(__args)...).first; } template<typename... _Args> iterator _M_emplace(const_iterator, false_type, _Args&&... __args); template<typename _Arg, typename _NodeGenerator> std::pair<iterator, bool> _M_insert(_Arg&&, const _NodeGenerator&, true_type, size_type = 1); template<typename _Arg, typename _NodeGenerator> iterator _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen, false_type __uk) { return _M_insert(cend(), std::forward<_Arg>(__arg), __node_gen, __uk); } // Insert with hint, not used when keys are unique. template<typename _Arg, typename _NodeGenerator> iterator _M_insert(const_iterator, _Arg&& __arg, const _NodeGenerator& __node_gen, true_type __uk) { return _M_insert(std::forward<_Arg>(__arg), __node_gen, __uk).first; } // Insert with hint when keys are not unique. template<typename _Arg, typename _NodeGenerator> iterator _M_insert(const_iterator, _Arg&&, const _NodeGenerator&, false_type); size_type _M_erase(true_type, const key_type&); size_type _M_erase(false_type, const key_type&); iterator _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n); public: // Emplace template<typename... _Args> __ireturn_type emplace(_Args&&... __args) { return _M_emplace(__unique_keys(), std::forward<_Args>(__args)...); } template<typename... _Args> iterator emplace_hint(const_iterator __hint, _Args&&... __args) { return _M_emplace(__hint, __unique_keys(), std::forward<_Args>(__args)...); } // Insert member functions via inheritance. // Erase iterator erase(const_iterator); // LWG 2059. iterator erase(iterator __it) { return erase(const_iterator(__it)); } size_type erase(const key_type& __k) { return _M_erase(__unique_keys(), __k); } iterator erase(const_iterator, const_iterator); void clear() noexcept; // Set number of buckets keeping it appropriate for container's number // of elements. void rehash(size_type __bkt_count); // DR 1189. // reserve, if present, comes from _Rehash_base. #if __cplusplus > 201402L /// Re-insert an extracted node into a container with unique keys. insert_return_type _M_reinsert_node(node_type&& __nh) { insert_return_type __ret; if (__nh.empty()) __ret.position = end(); else { __glibcxx_assert(get_allocator() == __nh.get_allocator()); const key_type& __k = __nh._M_key(); __hash_code __code = this->_M_hash_code(__k); size_type __bkt = _M_bucket_index(__k, __code); if (__node_type* __n = _M_find_node(__bkt, __k, __code)) { __ret.node = std::move(__nh); __ret.position = iterator(__n); __ret.inserted = false; } else { __ret.position = _M_insert_unique_node(__k, __bkt, __code, __nh._M_ptr); __nh._M_ptr = nullptr; __ret.inserted = true; } } return __ret; } /// Re-insert an extracted node into a container with equivalent keys. iterator _M_reinsert_node_multi(const_iterator __hint, node_type&& __nh) { if (__nh.empty()) return end(); __glibcxx_assert(get_allocator() == __nh.get_allocator()); const key_type& __k = __nh._M_key(); auto __code = this->_M_hash_code(__k); auto __ret = _M_insert_multi_node(__hint._M_cur, __k, __code, __nh._M_ptr); __nh._M_ptr = nullptr; return __ret; } private: node_type _M_extract_node(size_t __bkt, __node_base* __prev_n) { __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); if (__prev_n == _M_buckets[__bkt]) _M_remove_bucket_begin(__bkt, __n->_M_next(), __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0); else if (__n->_M_nxt) { size_type __next_bkt = _M_bucket_index(__n->_M_next()); if (__next_bkt != __bkt) _M_buckets[__next_bkt] = __prev_n; } __prev_n->_M_nxt = __n->_M_nxt; __n->_M_nxt = nullptr; --_M_element_count; return { __n, this->_M_node_allocator() }; } public: // Extract a node. node_type extract(const_iterator __pos) { size_t __bkt = _M_bucket_index(__pos._M_cur); return _M_extract_node(__bkt, _M_get_previous_node(__bkt, __pos._M_cur)); } /// Extract a node. node_type extract(const _Key& __k) { node_type __nh; __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); if (__node_base* __prev_node = _M_find_before_node(__bkt, __k, __code)) __nh = _M_extract_node(__bkt, __prev_node); return __nh; } /// Merge from a compatible container into one with unique keys. template<typename _Compatible_Hashtable> void _M_merge_unique(_Compatible_Hashtable& __src) noexcept { static_assert(is_same_v<typename _Compatible_Hashtable::node_type, node_type>, "Node types are compatible"); __glibcxx_assert(get_allocator() == __src.get_allocator()); auto __n_elt = __src.size(); for (auto __i = __src.begin(), __end = __src.end(); __i != __end;) { auto __pos = __i++; const key_type& __k = this->_M_extract()(*__pos); __hash_code __code = this->_M_hash_code(__k); size_type __bkt = _M_bucket_index(__k, __code); if (_M_find_node(__bkt, __k, __code) == nullptr) { auto __nh = __src.extract(__pos); _M_insert_unique_node(__k, __bkt, __code, __nh._M_ptr, __n_elt); __nh._M_ptr = nullptr; __n_elt = 1; } else if (__n_elt != 1) --__n_elt; } } /// Merge from a compatible container into one with equivalent keys. template<typename _Compatible_Hashtable> void _M_merge_multi(_Compatible_Hashtable& __src) noexcept { static_assert(is_same_v<typename _Compatible_Hashtable::node_type, node_type>, "Node types are compatible"); __glibcxx_assert(get_allocator() == __src.get_allocator()); this->reserve(size() + __src.size()); for (auto __i = __src.begin(), __end = __src.end(); __i != __end;) _M_reinsert_node_multi(cend(), __src.extract(__i++)); } #endif // C++17 private: // Helper rehash method used when keys are unique. void _M_rehash_aux(size_type __bkt_count, true_type); // Helper rehash method used when keys can be non-unique. void _M_rehash_aux(size_type __bkt_count, false_type); // Unconditionally change size of bucket array to n, restore // hash policy state to __state on exception. void _M_rehash(size_type __bkt_count, const __rehash_state& __state); }; // Definitions of class template _Hashtable's out-of-line member functions. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_bucket_begin(size_type __bkt) const -> __node_type* { __node_base* __n = _M_buckets[__bkt]; return __n ? static_cast<__node_type*>(__n->_M_nxt) : nullptr; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _Hashtable(size_type __bkt_count_hint, const _H1& __h1, const _H2& __h2, const _Hash& __h, const _Equal& __eq, const _ExtractKey& __exk, const allocator_type& __a) : _Hashtable(__h1, __h2, __h, __eq, __exk, __a) { auto __bkt_count = _M_rehash_policy._M_next_bkt(__bkt_count_hint); if (__bkt_count > _M_bucket_count) { _M_buckets = _M_allocate_buckets(__bkt_count); _M_bucket_count = __bkt_count; } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _InputIterator> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _Hashtable(_InputIterator __f, _InputIterator __l, size_type __bkt_count_hint, const _H1& __h1, const _H2& __h2, const _Hash& __h, const _Equal& __eq, const _ExtractKey& __exk, const allocator_type& __a) : _Hashtable(__h1, __h2, __h, __eq, __exk, __a) { auto __nb_elems = __detail::__distance_fw(__f, __l); auto __bkt_count = _M_rehash_policy._M_next_bkt( std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems), __bkt_count_hint)); if (__bkt_count > _M_bucket_count) { _M_buckets = _M_allocate_buckets(__bkt_count); _M_bucket_count = __bkt_count; } for (; __f != __l; ++__f) this->insert(*__f); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: operator=(const _Hashtable& __ht) -> _Hashtable& { if (&__ht == this) return *this; if (__node_alloc_traits::_S_propagate_on_copy_assign()) { auto& __this_alloc = this->_M_node_allocator(); auto& __that_alloc = __ht._M_node_allocator(); if (!__node_alloc_traits::_S_always_equal() && __this_alloc != __that_alloc) { // Replacement allocator cannot free existing storage. this->_M_deallocate_nodes(_M_begin()); _M_before_begin._M_nxt = nullptr; _M_deallocate_buckets(); _M_buckets = nullptr; std::__alloc_on_copy(__this_alloc, __that_alloc); __hashtable_base::operator=(__ht); _M_bucket_count = __ht._M_bucket_count; _M_element_count = __ht._M_element_count; _M_rehash_policy = __ht._M_rehash_policy; __alloc_node_gen_t __alloc_node_gen(*this); __try { _M_assign(__ht, __alloc_node_gen); } __catch(...) { // _M_assign took care of deallocating all memory. Now we // must make sure this instance remains in a usable state. _M_reset(); __throw_exception_again; } return *this; } std::__alloc_on_copy(__this_alloc, __that_alloc); } // Reuse allocated buckets and nodes. _M_assign_elements(__ht); return *this; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _Ht> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_assign_elements(_Ht&& __ht) { __bucket_type* __former_buckets = nullptr; std::size_t __former_bucket_count = _M_bucket_count; const __rehash_state& __former_state = _M_rehash_policy._M_state(); if (_M_bucket_count != __ht._M_bucket_count) { __former_buckets = _M_buckets; _M_buckets = _M_allocate_buckets(__ht._M_bucket_count); _M_bucket_count = __ht._M_bucket_count; } else __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type)); __try { __hashtable_base::operator=(std::forward<_Ht>(__ht)); _M_element_count = __ht._M_element_count; _M_rehash_policy = __ht._M_rehash_policy; __reuse_or_alloc_node_gen_t __roan(_M_begin(), *this); _M_before_begin._M_nxt = nullptr; _M_assign(std::forward<_Ht>(__ht), __roan); if (__former_buckets) _M_deallocate_buckets(__former_buckets, __former_bucket_count); } __catch(...) { if (__former_buckets) { // Restore previous buckets. _M_deallocate_buckets(); _M_rehash_policy._M_reset(__former_state); _M_buckets = __former_buckets; _M_bucket_count = __former_bucket_count; } __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type)); __throw_exception_again; } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _Ht, typename _NodeGenerator> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_assign(_Ht&& __ht, const _NodeGenerator& __node_gen) { __bucket_type* __buckets = nullptr; if (!_M_buckets) _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count); __try { if (!__ht._M_before_begin._M_nxt) return; // First deal with the special first node pointed to by // _M_before_begin. __node_type* __ht_n = __ht._M_begin(); __node_type* __this_n = __node_gen(__fwd_value_for<_Ht>(__ht_n->_M_v())); this->_M_copy_code(__this_n, __ht_n); _M_before_begin._M_nxt = __this_n; _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin; // Then deal with other nodes. __node_base* __prev_n = __this_n; for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next()) { __this_n = __node_gen(__fwd_value_for<_Ht>(__ht_n->_M_v())); __prev_n->_M_nxt = __this_n; this->_M_copy_code(__this_n, __ht_n); size_type __bkt = _M_bucket_index(__this_n); if (!_M_buckets[__bkt]) _M_buckets[__bkt] = __prev_n; __prev_n = __this_n; } } __catch(...) { clear(); if (__buckets) _M_deallocate_buckets(); __throw_exception_again; } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_reset() noexcept { _M_rehash_policy._M_reset(); _M_bucket_count = 1; _M_single_bucket = nullptr; _M_buckets = &_M_single_bucket; _M_before_begin._M_nxt = nullptr; _M_element_count = 0; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_move_assign(_Hashtable&& __ht, true_type) { this->_M_deallocate_nodes(_M_begin()); _M_deallocate_buckets(); __hashtable_base::operator=(std::move(__ht)); _M_rehash_policy = __ht._M_rehash_policy; if (!__ht._M_uses_single_bucket()) _M_buckets = __ht._M_buckets; else { _M_buckets = &_M_single_bucket; _M_single_bucket = __ht._M_single_bucket; } _M_bucket_count = __ht._M_bucket_count; _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt; _M_element_count = __ht._M_element_count; std::__alloc_on_move(this->_M_node_allocator(), __ht._M_node_allocator()); // Fix buckets containing the _M_before_begin pointers that can't be // moved. if (_M_begin()) _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; __ht._M_reset(); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_move_assign(_Hashtable&& __ht, false_type) { if (__ht._M_node_allocator() == this->_M_node_allocator()) _M_move_assign(std::move(__ht), true_type()); else { // Can't move memory, move elements then. _M_assign_elements(std::move(__ht)); __ht.clear(); } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _Hashtable(const _Hashtable& __ht) : __hashtable_base(__ht), __map_base(__ht), __rehash_base(__ht), __hashtable_alloc( __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())), _M_buckets(nullptr), _M_bucket_count(__ht._M_bucket_count), _M_element_count(__ht._M_element_count), _M_rehash_policy(__ht._M_rehash_policy) { __alloc_node_gen_t __alloc_node_gen(*this); _M_assign(__ht, __alloc_node_gen); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _Hashtable(_Hashtable&& __ht) noexcept : __hashtable_base(__ht), __map_base(__ht), __rehash_base(__ht), __hashtable_alloc(std::move(__ht._M_base_alloc())), _M_buckets(__ht._M_buckets), _M_bucket_count(__ht._M_bucket_count), _M_before_begin(__ht._M_before_begin._M_nxt), _M_element_count(__ht._M_element_count), _M_rehash_policy(__ht._M_rehash_policy) { // Update, if necessary, buckets if __ht is using its single bucket. if (__ht._M_uses_single_bucket()) { _M_buckets = &_M_single_bucket; _M_single_bucket = __ht._M_single_bucket; } // Update, if necessary, bucket pointing to before begin that hasn't // moved. if (_M_begin()) _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; __ht._M_reset(); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _Hashtable(const _Hashtable& __ht, const allocator_type& __a) : __hashtable_base(__ht), __map_base(__ht), __rehash_base(__ht), __hashtable_alloc(__node_alloc_type(__a)), _M_buckets(), _M_bucket_count(__ht._M_bucket_count), _M_element_count(__ht._M_element_count), _M_rehash_policy(__ht._M_rehash_policy) { __alloc_node_gen_t __alloc_node_gen(*this); _M_assign(__ht, __alloc_node_gen); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _Hashtable(_Hashtable&& __ht, const allocator_type& __a) : __hashtable_base(__ht), __map_base(__ht), __rehash_base(__ht), __hashtable_alloc(__node_alloc_type(__a)), _M_buckets(nullptr), _M_bucket_count(__ht._M_bucket_count), _M_element_count(__ht._M_element_count), _M_rehash_policy(__ht._M_rehash_policy) { if (__ht._M_node_allocator() == this->_M_node_allocator()) { if (__ht._M_uses_single_bucket()) { _M_buckets = &_M_single_bucket; _M_single_bucket = __ht._M_single_bucket; } else _M_buckets = __ht._M_buckets; _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt; // Update, if necessary, bucket pointing to before begin that hasn't // moved. if (_M_begin()) _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; __ht._M_reset(); } else { __alloc_node_gen_t __alloc_gen(*this); using _Fwd_Ht = typename conditional<__move_if_noexcept_cond<value_type>::value, const _Hashtable&, _Hashtable&&>::type; _M_assign(std::forward<_Fwd_Ht>(__ht), __alloc_gen); __ht.clear(); } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: ~_Hashtable() noexcept { clear(); _M_deallocate_buckets(); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: swap(_Hashtable& __x) noexcept(__and_<__is_nothrow_swappable<_H1>, __is_nothrow_swappable<_Equal>>::value) { // The only base class with member variables is hash_code_base. // We define _Hash_code_base::_M_swap because different // specializations have different members. this->_M_swap(__x); std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator()); std::swap(_M_rehash_policy, __x._M_rehash_policy); // Deal properly with potentially moved instances. if (this->_M_uses_single_bucket()) { if (!__x._M_uses_single_bucket()) { _M_buckets = __x._M_buckets; __x._M_buckets = &__x._M_single_bucket; } } else if (__x._M_uses_single_bucket()) { __x._M_buckets = _M_buckets; _M_buckets = &_M_single_bucket; } else std::swap(_M_buckets, __x._M_buckets); std::swap(_M_bucket_count, __x._M_bucket_count); std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt); std::swap(_M_element_count, __x._M_element_count); std::swap(_M_single_bucket, __x._M_single_bucket); // Fix buckets containing the _M_before_begin pointers that can't be // swapped. if (_M_begin()) _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; if (__x._M_begin()) __x._M_buckets[__x._M_bucket_index(__x._M_begin())] = &__x._M_before_begin; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: find(const key_type& __k) -> iterator { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); __node_type* __p = _M_find_node(__bkt, __k, __code); return __p ? iterator(__p) : end(); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: find(const key_type& __k) const -> const_iterator { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); __node_type* __p = _M_find_node(__bkt, __k, __code); return __p ? const_iterator(__p) : end(); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: count(const key_type& __k) const -> size_type { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); __node_type* __p = _M_bucket_begin(__bkt); if (!__p) return 0; std::size_t __result = 0; for (;; __p = __p->_M_next()) { if (this->_M_equals(__k, __code, __p)) ++__result; else if (__result) // All equivalent values are next to each other, if we // found a non-equivalent value after an equivalent one it // means that we won't find any new equivalent value. break; if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __bkt) break; } return __result; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: equal_range(const key_type& __k) -> pair<iterator, iterator> { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); __node_type* __p = _M_find_node(__bkt, __k, __code); if (__p) { __node_type* __p1 = __p->_M_next(); while (__p1 && _M_bucket_index(__p1) == __bkt && this->_M_equals(__k, __code, __p1)) __p1 = __p1->_M_next(); return std::make_pair(iterator(__p), iterator(__p1)); } else return std::make_pair(end(), end()); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: equal_range(const key_type& __k) const -> pair<const_iterator, const_iterator> { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); __node_type* __p = _M_find_node(__bkt, __k, __code); if (__p) { __node_type* __p1 = __p->_M_next(); while (__p1 && _M_bucket_index(__p1) == __bkt && this->_M_equals(__k, __code, __p1)) __p1 = __p1->_M_next(); return std::make_pair(const_iterator(__p), const_iterator(__p1)); } else return std::make_pair(end(), end()); } // Find the node whose key compares equal to k in the bucket bkt. // Return nullptr if no node is found. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_find_before_node(size_type __bkt, const key_type& __k, __hash_code __code) const -> __node_base* { __node_base* __prev_p = _M_buckets[__bkt]; if (!__prev_p) return nullptr; for (__node_type* __p = static_cast<__node_type*>(__prev_p->_M_nxt);; __p = __p->_M_next()) { if (this->_M_equals(__k, __code, __p)) return __prev_p; if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __bkt) break; __prev_p = __p; } return nullptr; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert_bucket_begin(size_type __bkt, __node_type* __node) { if (_M_buckets[__bkt]) { // Bucket is not empty, we just need to insert the new node // after the bucket before begin. __node->_M_nxt = _M_buckets[__bkt]->_M_nxt; _M_buckets[__bkt]->_M_nxt = __node; } else { // The bucket is empty, the new node is inserted at the // beginning of the singly-linked list and the bucket will // contain _M_before_begin pointer. __node->_M_nxt = _M_before_begin._M_nxt; _M_before_begin._M_nxt = __node; if (__node->_M_nxt) // We must update former begin bucket that is pointing to // _M_before_begin. _M_buckets[_M_bucket_index(__node->_M_next())] = __node; _M_buckets[__bkt] = &_M_before_begin; } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_remove_bucket_begin(size_type __bkt, __node_type* __next, size_type __next_bkt) { if (!__next || __next_bkt != __bkt) { // Bucket is now empty // First update next bucket if any if (__next) _M_buckets[__next_bkt] = _M_buckets[__bkt]; // Second update before begin node if necessary if (&_M_before_begin == _M_buckets[__bkt]) _M_before_begin._M_nxt = __next; _M_buckets[__bkt] = nullptr; } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_get_previous_node(size_type __bkt, __node_base* __n) -> __node_base* { __node_base* __prev_n = _M_buckets[__bkt]; while (__prev_n->_M_nxt != __n) __prev_n = __prev_n->_M_nxt; return __prev_n; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename... _Args> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_emplace(true_type, _Args&&... __args) -> pair<iterator, bool> { // First build the node to get access to the hash code _Scoped_node __node { this, std::forward<_Args>(__args)... }; const key_type& __k = this->_M_extract()(__node._M_node->_M_v()); __hash_code __code = this->_M_hash_code(__k); size_type __bkt = _M_bucket_index(__k, __code); if (__node_type* __p = _M_find_node(__bkt, __k, __code)) // There is already an equivalent node, no insertion return std::make_pair(iterator(__p), false); // Insert the node auto __pos = _M_insert_unique_node(__k, __bkt, __code, __node._M_node); __node._M_node = nullptr; return { __pos, true }; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename... _Args> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_emplace(const_iterator __hint, false_type, _Args&&... __args) -> iterator { // First build the node to get its hash code. _Scoped_node __node { this, std::forward<_Args>(__args)... }; const key_type& __k = this->_M_extract()(__node._M_node->_M_v()); __hash_code __code = this->_M_hash_code(__k); auto __pos = _M_insert_multi_node(__hint._M_cur, __k, __code, __node._M_node); __node._M_node = nullptr; return __pos; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert_unique_node(const key_type& __k, size_type __bkt, __hash_code __code, __node_type* __node, size_type __n_elt) -> iterator { const __rehash_state& __saved_state = _M_rehash_policy._M_state(); std::pair<bool, std::size_t> __do_rehash = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, __n_elt); if (__do_rehash.first) { _M_rehash(__do_rehash.second, __saved_state); __bkt = _M_bucket_index(__k, __code); } this->_M_store_code(__node, __code); // Always insert at the beginning of the bucket. _M_insert_bucket_begin(__bkt, __node); ++_M_element_count; return iterator(__node); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert_multi_node(__node_type* __hint, const key_type& __k, __hash_code __code, __node_type* __node) -> iterator { const __rehash_state& __saved_state = _M_rehash_policy._M_state(); std::pair<bool, std::size_t> __do_rehash = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1); if (__do_rehash.first) _M_rehash(__do_rehash.second, __saved_state); this->_M_store_code(__node, __code); size_type __bkt = _M_bucket_index(__k, __code); // Find the node before an equivalent one or use hint if it exists and // if it is equivalent. __node_base* __prev = __builtin_expect(__hint != nullptr, false) && this->_M_equals(__k, __code, __hint) ? __hint : _M_find_before_node(__bkt, __k, __code); if (__prev) { // Insert after the node before the equivalent one. __node->_M_nxt = __prev->_M_nxt; __prev->_M_nxt = __node; if (__builtin_expect(__prev == __hint, false)) // hint might be the last bucket node, in this case we need to // update next bucket. if (__node->_M_nxt && !this->_M_equals(__k, __code, __node->_M_next())) { size_type __next_bkt = _M_bucket_index(__node->_M_next()); if (__next_bkt != __bkt) _M_buckets[__next_bkt] = __node; } } else // The inserted node has no equivalent in the hashtable. We must // insert the new node at the beginning of the bucket to preserve // equivalent elements' relative positions. _M_insert_bucket_begin(__bkt, __node); ++_M_element_count; return iterator(__node); } // Insert v if no element with its key is already present. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _Arg, typename _NodeGenerator> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert(_Arg&& __v, const _NodeGenerator& __node_gen, true_type, size_type __n_elt) -> pair<iterator, bool> { const key_type& __k = this->_M_extract()(__v); __hash_code __code = this->_M_hash_code(__k); size_type __bkt = _M_bucket_index(__k, __code); if (__node_type* __node = _M_find_node(__bkt, __k, __code)) return { iterator(__node), false }; _Scoped_node __node{ __node_gen(std::forward<_Arg>(__v)), this }; auto __pos = _M_insert_unique_node(__k, __bkt, __code, __node._M_node, __n_elt); __node._M_node = nullptr; return { __pos, true }; } // Insert v unconditionally. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _Arg, typename _NodeGenerator> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert(const_iterator __hint, _Arg&& __v, const _NodeGenerator& __node_gen, false_type) -> iterator { // First compute the hash code so that we don't do anything if it // throws. __hash_code __code = this->_M_hash_code(this->_M_extract()(__v)); // Second allocate new node so that we don't rehash if it throws. _Scoped_node __node{ __node_gen(std::forward<_Arg>(__v)), this }; const key_type& __k = this->_M_extract()(__node._M_node->_M_v()); auto __pos = _M_insert_multi_node(__hint._M_cur, __k, __code, __node._M_node); __node._M_node = nullptr; return __pos; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: erase(const_iterator __it) -> iterator { __node_type* __n = __it._M_cur; std::size_t __bkt = _M_bucket_index(__n); // Look for previous node to unlink it from the erased one, this // is why we need buckets to contain the before begin to make // this search fast. __node_base* __prev_n = _M_get_previous_node(__bkt, __n); return _M_erase(__bkt, __prev_n, __n); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n) -> iterator { if (__prev_n == _M_buckets[__bkt]) _M_remove_bucket_begin(__bkt, __n->_M_next(), __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0); else if (__n->_M_nxt) { size_type __next_bkt = _M_bucket_index(__n->_M_next()); if (__next_bkt != __bkt) _M_buckets[__next_bkt] = __prev_n; } __prev_n->_M_nxt = __n->_M_nxt; iterator __result(__n->_M_next()); this->_M_deallocate_node(__n); --_M_element_count; return __result; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_erase(true_type, const key_type& __k) -> size_type { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); // Look for the node before the first matching node. __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); if (!__prev_n) return 0; // We found a matching node, erase it. __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); _M_erase(__bkt, __prev_n, __n); return 1; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_erase(false_type, const key_type& __k) -> size_type { __hash_code __code = this->_M_hash_code(__k); std::size_t __bkt = _M_bucket_index(__k, __code); // Look for the node before the first matching node. __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); if (!__prev_n) return 0; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 526. Is it undefined if a function in the standard changes // in parameters? // We use one loop to find all matching nodes and another to deallocate // them so that the key stays valid during the first loop. It might be // invalidated indirectly when destroying nodes. __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); __node_type* __n_last = __n; std::size_t __n_last_bkt = __bkt; do { __n_last = __n_last->_M_next(); if (!__n_last) break; __n_last_bkt = _M_bucket_index(__n_last); } while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last)); // Deallocate nodes. size_type __result = 0; do { __node_type* __p = __n->_M_next(); this->_M_deallocate_node(__n); __n = __p; ++__result; --_M_element_count; } while (__n != __n_last); if (__prev_n == _M_buckets[__bkt]) _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt); else if (__n_last && __n_last_bkt != __bkt) _M_buckets[__n_last_bkt] = __prev_n; __prev_n->_M_nxt = __n_last; return __result; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: erase(const_iterator __first, const_iterator __last) -> iterator { __node_type* __n = __first._M_cur; __node_type* __last_n = __last._M_cur; if (__n == __last_n) return iterator(__n); std::size_t __bkt = _M_bucket_index(__n); __node_base* __prev_n = _M_get_previous_node(__bkt, __n); bool __is_bucket_begin = __n == _M_bucket_begin(__bkt); std::size_t __n_bkt = __bkt; for (;;) { do { __node_type* __tmp = __n; __n = __n->_M_next(); this->_M_deallocate_node(__tmp); --_M_element_count; if (!__n) break; __n_bkt = _M_bucket_index(__n); } while (__n != __last_n && __n_bkt == __bkt); if (__is_bucket_begin) _M_remove_bucket_begin(__bkt, __n, __n_bkt); if (__n == __last_n) break; __is_bucket_begin = true; __bkt = __n_bkt; } if (__n && (__n_bkt != __bkt || __is_bucket_begin)) _M_buckets[__n_bkt] = __prev_n; __prev_n->_M_nxt = __n; return iterator(__n); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: clear() noexcept { this->_M_deallocate_nodes(_M_begin()); __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type)); _M_element_count = 0; _M_before_begin._M_nxt = nullptr; } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: rehash(size_type __bkt_count) { const __rehash_state& __saved_state = _M_rehash_policy._M_state(); __bkt_count = std::max(_M_rehash_policy._M_bkt_for_elements(_M_element_count + 1), __bkt_count); __bkt_count = _M_rehash_policy._M_next_bkt(__bkt_count); if (__bkt_count != _M_bucket_count) _M_rehash(__bkt_count, __saved_state); else // No rehash, restore previous state to keep it consistent with // container state. _M_rehash_policy._M_reset(__saved_state); } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_rehash(size_type __bkt_count, const __rehash_state& __state) { __try { _M_rehash_aux(__bkt_count, __unique_keys()); } __catch(...) { // A failure here means that buckets allocation failed. We only // have to restore hash policy previous state. _M_rehash_policy._M_reset(__state); __throw_exception_again; } } // Rehash when there is no equivalent elements. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_rehash_aux(size_type __bkt_count, true_type) { __bucket_type* __new_buckets = _M_allocate_buckets(__bkt_count); __node_type* __p = _M_begin(); _M_before_begin._M_nxt = nullptr; std::size_t __bbegin_bkt = 0; while (__p) { __node_type* __next = __p->_M_next(); std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __bkt_count); if (!__new_buckets[__bkt]) { __p->_M_nxt = _M_before_begin._M_nxt; _M_before_begin._M_nxt = __p; __new_buckets[__bkt] = &_M_before_begin; if (__p->_M_nxt) __new_buckets[__bbegin_bkt] = __p; __bbegin_bkt = __bkt; } else { __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; __new_buckets[__bkt]->_M_nxt = __p; } __p = __next; } _M_deallocate_buckets(); _M_bucket_count = __bkt_count; _M_buckets = __new_buckets; } // Rehash when there can be equivalent elements, preserve their relative // order. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> void _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_rehash_aux(size_type __bkt_count, false_type) { __bucket_type* __new_buckets = _M_allocate_buckets(__bkt_count); __node_type* __p = _M_begin(); _M_before_begin._M_nxt = nullptr; std::size_t __bbegin_bkt = 0; std::size_t __prev_bkt = 0; __node_type* __prev_p = nullptr; bool __check_bucket = false; while (__p) { __node_type* __next = __p->_M_next(); std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __bkt_count); if (__prev_p && __prev_bkt == __bkt) { // Previous insert was already in this bucket, we insert after // the previously inserted one to preserve equivalent elements // relative order. __p->_M_nxt = __prev_p->_M_nxt; __prev_p->_M_nxt = __p; // Inserting after a node in a bucket require to check that we // haven't change the bucket last node, in this case next // bucket containing its before begin node must be updated. We // schedule a check as soon as we move out of the sequence of // equivalent nodes to limit the number of checks. __check_bucket = true; } else { if (__check_bucket) { // Check if we shall update the next bucket because of // insertions into __prev_bkt bucket. if (__prev_p->_M_nxt) { std::size_t __next_bkt = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __bkt_count); if (__next_bkt != __prev_bkt) __new_buckets[__next_bkt] = __prev_p; } __check_bucket = false; } if (!__new_buckets[__bkt]) { __p->_M_nxt = _M_before_begin._M_nxt; _M_before_begin._M_nxt = __p; __new_buckets[__bkt] = &_M_before_begin; if (__p->_M_nxt) __new_buckets[__bbegin_bkt] = __p; __bbegin_bkt = __bkt; } else { __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; __new_buckets[__bkt]->_M_nxt = __p; } } __prev_p = __p; __prev_bkt = __bkt; __p = __next; } if (__check_bucket && __prev_p->_M_nxt) { std::size_t __next_bkt = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __bkt_count); if (__next_bkt != __prev_bkt) __new_buckets[__next_bkt] = __prev_p; } _M_deallocate_buckets(); _M_bucket_count = __bkt_count; _M_buckets = __new_buckets; } #if __cplusplus > 201402L template<typename, typename, typename> class _Hash_merge_helper { }; #endif // C++17 #if __cpp_deduction_guides >= 201606 // Used to constrain deduction guides template<typename _Hash> using _RequireNotAllocatorOrIntegral = __enable_if_t<!__or_<is_integral<_Hash>, __is_allocator<_Hash>>::value>; #endif _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // _HASHTABLE_H