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- // hashtable.h header -*- C++ -*-
- // Copyright (C) 2007-2022 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>
- #include <bits/enable_special_members.h>
- #if __cplusplus > 201402L
- # include <bits/node_handle.h>
- #endif
- namespace std _GLIBCXX_VISIBILITY(default)
- {
- _GLIBCXX_BEGIN_NAMESPACE_VERSION
- /// @cond undocumented
- 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&>>>;
- // Helper to conditionally delete the default constructor.
- // The _Hash_node_base type is used to distinguish this specialization
- // from any other potentially-overlapping subobjects of the hashtable.
- template<typename _Equal, typename _Hash, typename _Allocator>
- using _Hashtable_enable_default_ctor
- = _Enable_default_constructor<__and_<is_default_constructible<_Equal>,
- is_default_constructible<_Hash>,
- is_default_constructible<_Allocator>>{},
- __detail::_Hash_node_base>;
- /**
- * 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 _Hash 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 _RangeHash 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 _Unused Not used.
- *
- * @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 for n_ins insertions.
- * 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_base* 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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- class _Hashtable
- : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _Traits>,
- public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>,
- public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>,
- public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>,
- public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>,
- private __detail::_Hashtable_alloc<
- __alloc_rebind<_Alloc,
- __detail::_Hash_node<_Value,
- _Traits::__hash_cached::value>>>,
- private _Hashtable_enable_default_ctor<_Equal, _Hash, _Alloc>
- {
- 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 __constant_iterators = typename __traits_type::__constant_iterators;
- 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 __node_value_type =
- __detail::_Hash_node_value<_Value, __hash_cached::value>;
- using __node_ptr = typename __hashtable_alloc::__node_ptr;
- 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 __node_base_ptr = typename __hashtable_alloc::__node_base_ptr;
- using __buckets_ptr = typename __hashtable_alloc::__buckets_ptr;
- using __insert_base = __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey,
- _Equal, _Hash,
- _RangeHash, _Unused,
- _RehashPolicy, _Traits>;
- using __enable_default_ctor
- = _Hashtable_enable_default_ctor<_Equal, _Hash, _Alloc>;
- 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;
- using iterator = typename __insert_base::iterator;
- using const_iterator = typename __insert_base::const_iterator;
- using local_iterator = __detail::_Local_iterator<key_type, _Value,
- _ExtractKey, _Hash, _RangeHash, _Unused,
- __constant_iterators::value,
- __hash_cached::value>;
- using const_local_iterator = __detail::_Local_const_iterator<
- key_type, _Value,
- _ExtractKey, _Hash, _RangeHash, _Unused,
- __constant_iterators::value, __hash_cached::value>;
- private:
- using __rehash_type = _RehashPolicy;
- using __rehash_state = typename __rehash_type::_State;
- using __unique_keys = typename __traits_type::__unique_keys;
- using __hashtable_base = __detail::
- _Hashtable_base<_Key, _Value, _ExtractKey,
- _Equal, _Hash, _RangeHash, _Unused, _Traits>;
- using __hash_code_base = typename __hashtable_base::__hash_code_base;
- using __hash_code = typename __hashtable_base::__hash_code;
- using __ireturn_type = typename __insert_base::__ireturn_type;
- using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey,
- _Equal, _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>;
- using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc,
- _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>;
- using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey,
- _Equal, _Hash, _RangeHash, _Unused,
- _RehashPolicy, _Traits>;
- using __reuse_or_alloc_node_gen_t =
- __detail::_ReuseOrAllocNode<__node_alloc_type>;
- using __alloc_node_gen_t =
- __detail::_AllocNode<__node_alloc_type>;
- using __node_builder_t =
- __detail::_NodeBuilder<_ExtractKey>;
- // 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_ptr __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_ptr _M_node;
- };
- template<typename _Ht>
- static constexpr
- __conditional_t<std::is_lvalue_reference<_Ht>::value,
- const value_type&, value_type&&>
- __fwd_value_for(value_type& __val) noexcept
- { return std::move(__val); }
- // 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; };
- // To get bucket index we need _RangeHash not to throw.
- static_assert(is_nothrow_default_constructible<_RangeHash>::value,
- "Functor used to map hash code to bucket index"
- " must be nothrow default constructible");
- static_assert(noexcept(
- std::declval<const _RangeHash&>()((std::size_t)0, (std::size_t)0)),
- "Functor used to map hash code to bucket index must be"
- " noexcept");
- // To compute bucket index we also need _ExtratKey not to throw.
- static_assert(is_nothrow_default_constructible<_ExtractKey>::value,
- "_ExtractKey must be nothrow default constructible");
- static_assert(noexcept(
- std::declval<const _ExtractKey&>()(std::declval<_Value>())),
- "_ExtractKey functor must be noexcept invocable");
- template<typename _Keya, typename _Valuea, typename _Alloca,
- typename _ExtractKeya, typename _Equala,
- typename _Hasha, typename _RangeHasha, typename _Unuseda,
- typename _RehashPolicya, typename _Traitsa,
- bool _Unique_keysa>
- friend struct __detail::_Map_base;
- template<typename _Keya, typename _Valuea, typename _Alloca,
- typename _ExtractKeya, typename _Equala,
- typename _Hasha, typename _RangeHasha, typename _Unuseda,
- typename _RehashPolicya, typename _Traitsa>
- friend struct __detail::_Insert_base;
- template<typename _Keya, typename _Valuea, typename _Alloca,
- typename _ExtractKeya, typename _Equala,
- typename _Hasha, typename _RangeHasha, typename _Unuseda,
- typename _RehashPolicya, typename _Traitsa,
- bool _Constant_iteratorsa>
- friend struct __detail::_Insert;
- template<typename _Keya, typename _Valuea, typename _Alloca,
- typename _ExtractKeya, typename _Equala,
- typename _Hasha, typename _RangeHasha, typename _Unuseda,
- 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;
- #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:
- __buckets_ptr _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.
- __node_base_ptr _M_single_bucket = nullptr;
- void
- _M_update_bbegin()
- {
- if (_M_begin())
- _M_buckets[_M_bucket_index(*_M_begin())] = &_M_before_begin;
- }
- void
- _M_update_bbegin(__node_ptr __n)
- {
- _M_before_begin._M_nxt = __n;
- _M_update_bbegin();
- }
- bool
- _M_uses_single_bucket(__buckets_ptr __bkts) const
- { return __builtin_expect(__bkts == &_M_single_bucket, false); }
- bool
- _M_uses_single_bucket() const
- { return _M_uses_single_bucket(_M_buckets); }
- static constexpr size_t
- __small_size_threshold() noexcept
- {
- return
- __detail::_Hashtable_hash_traits<_Hash>::__small_size_threshold();
- }
- __hashtable_alloc&
- _M_base_alloc() { return *this; }
- __buckets_ptr
- _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(__buckets_ptr __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_ptr
- _M_bucket_begin(size_type __bkt) const;
- __node_ptr
- _M_begin() const
- { return static_cast<__node_ptr>(_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 _Hash& __h, const _Equal& __eq,
- const allocator_type& __a)
- : __hashtable_base(__h, __eq),
- __hashtable_alloc(__node_alloc_type(__a)),
- __enable_default_ctor(_Enable_default_constructor_tag{})
- { }
- template<bool _No_realloc = true>
- static constexpr bool
- _S_nothrow_move()
- {
- #if __cplusplus <= 201402L
- return __and_<__bool_constant<_No_realloc>,
- is_nothrow_copy_constructible<_Hash>,
- is_nothrow_copy_constructible<_Equal>>::value;
- #else
- if constexpr (_No_realloc)
- if constexpr (is_nothrow_copy_constructible<_Hash>())
- return is_nothrow_copy_constructible<_Equal>();
- return false;
- #endif
- }
- _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a,
- true_type /* alloc always equal */)
- noexcept(_S_nothrow_move());
- _Hashtable(_Hashtable&&, __node_alloc_type&&,
- false_type /* alloc always equal */);
- template<typename _InputIterator>
- _Hashtable(_InputIterator __first, _InputIterator __last,
- size_type __bkt_count_hint,
- const _Hash&, const _Equal&, const allocator_type&,
- true_type __uks);
- template<typename _InputIterator>
- _Hashtable(_InputIterator __first, _InputIterator __last,
- size_type __bkt_count_hint,
- const _Hash&, const _Equal&, const allocator_type&,
- false_type __uks);
- public:
- // Constructor, destructor, assignment, swap
- _Hashtable() = default;
- _Hashtable(const _Hashtable&);
- _Hashtable(const _Hashtable&, const allocator_type&);
- explicit
- _Hashtable(size_type __bkt_count_hint,
- const _Hash& __hf = _Hash(),
- const key_equal& __eql = key_equal(),
- const allocator_type& __a = allocator_type());
- // Use delegating constructors.
- _Hashtable(_Hashtable&& __ht)
- noexcept(_S_nothrow_move())
- : _Hashtable(std::move(__ht), std::move(__ht._M_node_allocator()),
- true_type{})
- { }
- _Hashtable(_Hashtable&& __ht, const allocator_type& __a)
- noexcept(_S_nothrow_move<__node_alloc_traits::_S_always_equal()>())
- : _Hashtable(std::move(__ht), __node_alloc_type(__a),
- typename __node_alloc_traits::is_always_equal{})
- { }
- explicit
- _Hashtable(const allocator_type& __a)
- : __hashtable_alloc(__node_alloc_type(__a)),
- __enable_default_ctor(_Enable_default_constructor_tag{})
- { }
- template<typename _InputIterator>
- _Hashtable(_InputIterator __f, _InputIterator __l,
- size_type __bkt_count_hint = 0,
- const _Hash& __hf = _Hash(),
- const key_equal& __eql = key_equal(),
- const allocator_type& __a = allocator_type())
- : _Hashtable(__f, __l, __bkt_count_hint, __hf, __eql, __a,
- __unique_keys{})
- { }
- _Hashtable(initializer_list<value_type> __l,
- size_type __bkt_count_hint = 0,
- const _Hash& __hf = _Hash(),
- const key_equal& __eql = key_equal(),
- const allocator_type& __a = allocator_type())
- : _Hashtable(__l.begin(), __l.end(), __bkt_count_hint,
- __hf, __eql, __a, __unique_keys{})
- { }
- _Hashtable&
- operator=(const _Hashtable& __ht);
- _Hashtable&
- operator=(_Hashtable&& __ht)
- noexcept(__node_alloc_traits::_S_nothrow_move()
- && is_nothrow_move_assignable<_Hash>::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();
- // We consider that all elements of __l are going to be inserted.
- auto __l_bkt_count = _M_rehash_policy._M_bkt_for_elements(__l.size());
- // Do not shrink to keep potential user reservation.
- if (_M_bucket_count < __l_bkt_count)
- rehash(__l_bkt_count);
- this->_M_insert_range(__l.begin(), __l.end(), __roan, __unique_keys{});
- return *this;
- }
- ~_Hashtable() noexcept;
- void
- swap(_Hashtable&)
- noexcept(__and_<__is_nothrow_swappable<_Hash>,
- __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(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;
- #if __cplusplus >= 202002L
- #define __cpp_lib_generic_unordered_lookup 201811L
- template<typename _Kt,
- typename = __has_is_transparent_t<_Hash, _Kt>,
- typename = __has_is_transparent_t<_Equal, _Kt>>
- iterator
- _M_find_tr(const _Kt& __k);
- template<typename _Kt,
- typename = __has_is_transparent_t<_Hash, _Kt>,
- typename = __has_is_transparent_t<_Equal, _Kt>>
- const_iterator
- _M_find_tr(const _Kt& __k) const;
- template<typename _Kt,
- typename = __has_is_transparent_t<_Hash, _Kt>,
- typename = __has_is_transparent_t<_Equal, _Kt>>
- size_type
- _M_count_tr(const _Kt& __k) const;
- template<typename _Kt,
- typename = __has_is_transparent_t<_Hash, _Kt>,
- typename = __has_is_transparent_t<_Equal, _Kt>>
- pair<iterator, iterator>
- _M_equal_range_tr(const _Kt& __k);
- template<typename _Kt,
- typename = __has_is_transparent_t<_Hash, _Kt>,
- typename = __has_is_transparent_t<_Equal, _Kt>>
- pair<const_iterator, const_iterator>
- _M_equal_range_tr(const _Kt& __k) const;
- #endif // C++20
- private:
- // Bucket index computation helpers.
- size_type
- _M_bucket_index(const __node_value_type& __n) const noexcept
- { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); }
- size_type
- _M_bucket_index(__hash_code __c) const
- { return __hash_code_base::_M_bucket_index(__c, _M_bucket_count); }
- __node_base_ptr
- _M_find_before_node(const key_type&);
- // Find and insert helper functions and types
- // Find the node before the one matching the criteria.
- __node_base_ptr
- _M_find_before_node(size_type, const key_type&, __hash_code) const;
- template<typename _Kt>
- __node_base_ptr
- _M_find_before_node_tr(size_type, const _Kt&, __hash_code) const;
- __node_ptr
- _M_find_node(size_type __bkt, const key_type& __key,
- __hash_code __c) const
- {
- __node_base_ptr __before_n = _M_find_before_node(__bkt, __key, __c);
- if (__before_n)
- return static_cast<__node_ptr>(__before_n->_M_nxt);
- return nullptr;
- }
- template<typename _Kt>
- __node_ptr
- _M_find_node_tr(size_type __bkt, const _Kt& __key,
- __hash_code __c) const
- {
- auto __before_n = _M_find_before_node_tr(__bkt, __key, __c);
- if (__before_n)
- return static_cast<__node_ptr>(__before_n->_M_nxt);
- return nullptr;
- }
- // Insert a node at the beginning of a bucket.
- void
- _M_insert_bucket_begin(size_type, __node_ptr);
- // Remove the bucket first node
- void
- _M_remove_bucket_begin(size_type __bkt, __node_ptr __next_n,
- size_type __next_bkt);
- // Get the node before __n in the bucket __bkt
- __node_base_ptr
- _M_get_previous_node(size_type __bkt, __node_ptr __n);
- pair<const_iterator, __hash_code>
- _M_compute_hash_code(const_iterator __hint, const key_type& __k) const;
- // Insert node __n with 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(size_type __bkt, __hash_code,
- __node_ptr __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_ptr __hint,
- __hash_code __code, __node_ptr __n);
- template<typename... _Args>
- std::pair<iterator, bool>
- _M_emplace(true_type __uks, _Args&&... __args);
- template<typename... _Args>
- iterator
- _M_emplace(false_type __uks, _Args&&... __args)
- { return _M_emplace(cend(), __uks, std::forward<_Args>(__args)...); }
- // Emplace with hint, useless when keys are unique.
- template<typename... _Args>
- iterator
- _M_emplace(const_iterator, true_type __uks, _Args&&... __args)
- { return _M_emplace(__uks, std::forward<_Args>(__args)...).first; }
- template<typename... _Args>
- iterator
- _M_emplace(const_iterator, false_type __uks, _Args&&... __args);
- template<typename _Kt, typename _Arg, typename _NodeGenerator>
- std::pair<iterator, bool>
- _M_insert_unique(_Kt&&, _Arg&&, const _NodeGenerator&);
- template<typename _Kt>
- static __conditional_t<
- __and_<__is_nothrow_invocable<_Hash&, const key_type&>,
- __not_<__is_nothrow_invocable<_Hash&, _Kt>>>::value,
- key_type, _Kt&&>
- _S_forward_key(_Kt&& __k)
- { return std::forward<_Kt>(__k); }
- static const key_type&
- _S_forward_key(const key_type& __k)
- { return __k; }
- static key_type&&
- _S_forward_key(key_type&& __k)
- { return std::move(__k); }
- template<typename _Arg, typename _NodeGenerator>
- std::pair<iterator, bool>
- _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen,
- true_type /* __uks */)
- {
- return _M_insert_unique(
- _S_forward_key(_ExtractKey{}(std::forward<_Arg>(__arg))),
- std::forward<_Arg>(__arg), __node_gen);
- }
- template<typename _Arg, typename _NodeGenerator>
- iterator
- _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen,
- false_type __uks)
- {
- return _M_insert(cend(), std::forward<_Arg>(__arg), __node_gen,
- __uks);
- }
- // 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 __uks)
- {
- return
- _M_insert(std::forward<_Arg>(__arg), __node_gen, __uks).first;
- }
- // Insert with hint when keys are not unique.
- template<typename _Arg, typename _NodeGenerator>
- iterator
- _M_insert(const_iterator, _Arg&&,
- const _NodeGenerator&, false_type __uks);
- size_type
- _M_erase(true_type __uks, const key_type&);
- size_type
- _M_erase(false_type __uks, const key_type&);
- iterator
- _M_erase(size_type __bkt, __node_base_ptr __prev_n, __node_ptr __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(__code);
- if (__node_ptr __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(__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, __code, __nh._M_ptr);
- __nh._M_ptr = nullptr;
- return __ret;
- }
- private:
- node_type
- _M_extract_node(size_t __bkt, __node_base_ptr __prev_n)
- {
- __node_ptr __n = static_cast<__node_ptr>(__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(__code);
- if (__node_base_ptr __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)
- {
- 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.cbegin(), __end = __src.cend(); __i != __end;)
- {
- auto __pos = __i++;
- const key_type& __k = _ExtractKey{}(*__pos);
- __hash_code __code
- = this->_M_hash_code(__src.hash_function(), *__pos._M_cur);
- size_type __bkt = _M_bucket_index(__code);
- if (_M_find_node(__bkt, __k, __code) == nullptr)
- {
- auto __nh = __src.extract(__pos);
- _M_insert_unique_node(__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)
- {
- static_assert(is_same_v<typename _Compatible_Hashtable::node_type,
- node_type>, "Node types are compatible");
- __glibcxx_assert(get_allocator() == __src.get_allocator());
- __node_ptr __hint = nullptr;
- this->reserve(size() + __src.size());
- for (auto __i = __src.cbegin(), __end = __src.cend(); __i != __end;)
- {
- auto __pos = __i++;
- __hash_code __code
- = this->_M_hash_code(__src.hash_function(), *__pos._M_cur);
- auto __nh = __src.extract(__pos);
- __hint = _M_insert_multi_node(__hint, __code, __nh._M_ptr)._M_cur;
- __nh._M_ptr = nullptr;
- }
- }
- #endif // C++17
- private:
- // Helper rehash method used when keys are unique.
- void _M_rehash_aux(size_type __bkt_count, true_type __uks);
- // Helper rehash method used when keys can be non-unique.
- void _M_rehash_aux(size_type __bkt_count, false_type __uks);
- // 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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_bucket_begin(size_type __bkt) const
- -> __node_ptr
- {
- __node_base_ptr __n = _M_buckets[__bkt];
- return __n ? static_cast<__node_ptr>(__n->_M_nxt) : nullptr;
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _Hashtable(size_type __bkt_count_hint,
- const _Hash& __h, const _Equal& __eq, const allocator_type& __a)
- : _Hashtable(__h, __eq, __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _InputIterator>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _Hashtable(_InputIterator __f, _InputIterator __l,
- size_type __bkt_count_hint,
- const _Hash& __h, const _Equal& __eq,
- const allocator_type& __a, true_type /* __uks */)
- : _Hashtable(__bkt_count_hint, __h, __eq, __a)
- {
- for (; __f != __l; ++__f)
- this->insert(*__f);
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _InputIterator>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _Hashtable(_InputIterator __f, _InputIterator __l,
- size_type __bkt_count_hint,
- const _Hash& __h, const _Equal& __eq,
- const allocator_type& __a, false_type /* __uks */)
- : _Hashtable(__h, __eq, __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Ht>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_assign_elements(_Ht&& __ht)
- {
- __buckets_ptr __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(__node_base_ptr));
- __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(__node_base_ptr));
- __throw_exception_again;
- }
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Ht, typename _NodeGenerator>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_assign(_Ht&& __ht, const _NodeGenerator& __node_gen)
- {
- __buckets_ptr __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_ptr __ht_n = __ht._M_begin();
- __node_ptr __this_n
- = __node_gen(__fwd_value_for<_Ht>(__ht_n->_M_v()));
- this->_M_copy_code(*__this_n, *__ht_n);
- _M_update_bbegin(__this_n);
- // Then deal with other nodes.
- __node_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_move_assign(_Hashtable&& __ht, true_type)
- {
- if (__builtin_expect(std::__addressof(__ht) == this, false))
- return;
- 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 bucket containing the _M_before_begin pointer that can't be moved.
- _M_update_bbegin();
- __ht._M_reset();
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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())),
- __enable_default_ctor(__ht),
- _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a,
- true_type /* alloc always equal */)
- noexcept(_S_nothrow_move())
- : __hashtable_base(__ht),
- __map_base(__ht),
- __rehash_base(__ht),
- __hashtable_alloc(std::move(__a)),
- __enable_default_ctor(__ht),
- _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 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;
- }
- // Fix bucket containing the _M_before_begin pointer that can't be moved.
- _M_update_bbegin();
- __ht._M_reset();
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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)),
- __enable_default_ctor(__ht),
- _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a,
- false_type /* alloc always equal */)
- : __hashtable_base(__ht),
- __map_base(__ht),
- __rehash_base(__ht),
- __hashtable_alloc(std::move(__a)),
- __enable_default_ctor(__ht),
- _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;
- // Fix bucket containing the _M_before_begin pointer that can't be
- // moved.
- _M_update_bbegin(__ht._M_begin());
- __ht._M_reset();
- }
- else
- {
- __alloc_node_gen_t __alloc_gen(*this);
- using _Fwd_Ht = __conditional_t<
- __move_if_noexcept_cond<value_type>::value,
- const _Hashtable&, _Hashtable&&>;
- _M_assign(std::forward<_Fwd_Ht>(__ht), __alloc_gen);
- __ht.clear();
- }
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- ~_Hashtable() noexcept
- {
- // Getting a bucket index from a node shall not throw because it is used
- // in methods (erase, swap...) that shall not throw. Need a complete
- // type to check this, so do it in the destructor not at class scope.
- static_assert(noexcept(declval<const __hash_code_base_access&>()
- ._M_bucket_index(declval<const __node_value_type&>(),
- (std::size_t)0)),
- "Cache the hash code or qualify your functors involved"
- " in hash code and bucket index computation with noexcept");
- clear();
- _M_deallocate_buckets();
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- swap(_Hashtable& __x)
- noexcept(__and_<__is_nothrow_swappable<_Hash>,
- __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.
- _M_update_bbegin();
- __x._M_update_bbegin();
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- find(const key_type& __k)
- -> iterator
- {
- if (size() <= __small_size_threshold())
- {
- for (auto __it = begin(); __it != end(); ++__it)
- if (this->_M_key_equals(__k, *__it._M_cur))
- return __it;
- return end();
- }
- __hash_code __code = this->_M_hash_code(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- return iterator(_M_find_node(__bkt, __k, __code));
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- find(const key_type& __k) const
- -> const_iterator
- {
- if (size() <= __small_size_threshold())
- {
- for (auto __it = begin(); __it != end(); ++__it)
- if (this->_M_key_equals(__k, *__it._M_cur))
- return __it;
- return end();
- }
- __hash_code __code = this->_M_hash_code(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- return const_iterator(_M_find_node(__bkt, __k, __code));
- }
- #if __cplusplus > 201703L
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt, typename, typename>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_find_tr(const _Kt& __k)
- -> iterator
- {
- __hash_code __code = this->_M_hash_code_tr(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- return iterator(_M_find_node_tr(__bkt, __k, __code));
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt, typename, typename>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_find_tr(const _Kt& __k) const
- -> const_iterator
- {
- __hash_code __code = this->_M_hash_code_tr(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- return const_iterator(_M_find_node_tr(__bkt, __k, __code));
- }
- #endif
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- count(const key_type& __k) const
- -> size_type
- {
- auto __it = find(__k);
- if (!__it._M_cur)
- return 0;
- if (__unique_keys::value)
- return 1;
- // All equivalent values are next to each other, if we find a
- // non-equivalent value after an equivalent one it means that we won't
- // find any new equivalent value.
- size_type __result = 1;
- for (auto __ref = __it++;
- __it._M_cur && this->_M_node_equals(*__ref._M_cur, *__it._M_cur);
- ++__it)
- ++__result;
- return __result;
- }
- #if __cplusplus > 201703L
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt, typename, typename>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_count_tr(const _Kt& __k) const
- -> size_type
- {
- __hash_code __code = this->_M_hash_code_tr(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- auto __n = _M_find_node_tr(__bkt, __k, __code);
- if (!__n)
- return 0;
- // All equivalent values are next to each other, if we find a
- // non-equivalent value after an equivalent one it means that we won't
- // find any new equivalent value.
- iterator __it(__n);
- size_type __result = 1;
- for (++__it;
- __it._M_cur && this->_M_equals_tr(__k, __code, *__it._M_cur);
- ++__it)
- ++__result;
- return __result;
- }
- #endif
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- equal_range(const key_type& __k)
- -> pair<iterator, iterator>
- {
- auto __ite = find(__k);
- if (!__ite._M_cur)
- return { __ite, __ite };
- auto __beg = __ite++;
- if (__unique_keys::value)
- return { __beg, __ite };
- // All equivalent values are next to each other, if we find a
- // non-equivalent value after an equivalent one it means that we won't
- // find any new equivalent value.
- while (__ite._M_cur && this->_M_node_equals(*__beg._M_cur, *__ite._M_cur))
- ++__ite;
- return { __beg, __ite };
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- equal_range(const key_type& __k) const
- -> pair<const_iterator, const_iterator>
- {
- auto __ite = find(__k);
- if (!__ite._M_cur)
- return { __ite, __ite };
- auto __beg = __ite++;
- if (__unique_keys::value)
- return { __beg, __ite };
- // All equivalent values are next to each other, if we find a
- // non-equivalent value after an equivalent one it means that we won't
- // find any new equivalent value.
- while (__ite._M_cur && this->_M_node_equals(*__beg._M_cur, *__ite._M_cur))
- ++__ite;
- return { __beg, __ite };
- }
- #if __cplusplus > 201703L
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt, typename, typename>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_equal_range_tr(const _Kt& __k)
- -> pair<iterator, iterator>
- {
- __hash_code __code = this->_M_hash_code_tr(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- auto __n = _M_find_node_tr(__bkt, __k, __code);
- iterator __ite(__n);
- if (!__n)
- return { __ite, __ite };
- // All equivalent values are next to each other, if we find a
- // non-equivalent value after an equivalent one it means that we won't
- // find any new equivalent value.
- auto __beg = __ite++;
- while (__ite._M_cur && this->_M_equals_tr(__k, __code, *__ite._M_cur))
- ++__ite;
- return { __beg, __ite };
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt, typename, typename>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_equal_range_tr(const _Kt& __k) const
- -> pair<const_iterator, const_iterator>
- {
- __hash_code __code = this->_M_hash_code_tr(__k);
- std::size_t __bkt = _M_bucket_index(__code);
- auto __n = _M_find_node_tr(__bkt, __k, __code);
- const_iterator __ite(__n);
- if (!__n)
- return { __ite, __ite };
- // All equivalent values are next to each other, if we find a
- // non-equivalent value after an equivalent one it means that we won't
- // find any new equivalent value.
- auto __beg = __ite++;
- while (__ite._M_cur && this->_M_equals_tr(__k, __code, *__ite._M_cur))
- ++__ite;
- return { __beg, __ite };
- }
- #endif
- // Find the node before the one whose key compares equal to k.
- // Return nullptr if no node is found.
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_find_before_node(const key_type& __k)
- -> __node_base_ptr
- {
- __node_base_ptr __prev_p = &_M_before_begin;
- if (!__prev_p->_M_nxt)
- return nullptr;
- for (__node_ptr __p = static_cast<__node_ptr>(__prev_p->_M_nxt);
- __p != nullptr;
- __p = __p->_M_next())
- {
- if (this->_M_key_equals(__k, *__p))
- return __prev_p;
- __prev_p = __p;
- }
- return nullptr;
- }
- // Find the node before the one 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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_find_before_node(size_type __bkt, const key_type& __k,
- __hash_code __code) const
- -> __node_base_ptr
- {
- __node_base_ptr __prev_p = _M_buckets[__bkt];
- if (!__prev_p)
- return nullptr;
- for (__node_ptr __p = static_cast<__node_ptr>(__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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_find_before_node_tr(size_type __bkt, const _Kt& __k,
- __hash_code __code) const
- -> __node_base_ptr
- {
- __node_base_ptr __prev_p = _M_buckets[__bkt];
- if (!__prev_p)
- return nullptr;
- for (__node_ptr __p = static_cast<__node_ptr>(__prev_p->_M_nxt);;
- __p = __p->_M_next())
- {
- if (this->_M_equals_tr(__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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_insert_bucket_begin(size_type __bkt, __node_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_remove_bucket_begin(size_type __bkt, __node_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_get_previous_node(size_type __bkt, __node_ptr __n)
- -> __node_base_ptr
- {
- __node_base_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename... _Args>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_emplace(true_type /* __uks */, _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 = _ExtractKey{}(__node._M_node->_M_v());
- if (size() <= __small_size_threshold())
- {
- for (auto __it = begin(); __it != end(); ++__it)
- if (this->_M_key_equals(__k, *__it._M_cur))
- // There is already an equivalent node, no insertion
- return { __it, false };
- }
- __hash_code __code = this->_M_hash_code(__k);
- size_type __bkt = _M_bucket_index(__code);
- if (size() > __small_size_threshold())
- if (__node_ptr __p = _M_find_node(__bkt, __k, __code))
- // There is already an equivalent node, no insertion
- return { iterator(__p), false };
- // Insert the node
- auto __pos = _M_insert_unique_node(__bkt, __code, __node._M_node);
- __node._M_node = nullptr;
- return { __pos, true };
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename... _Args>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_emplace(const_iterator __hint, false_type /* __uks */,
- _Args&&... __args)
- -> iterator
- {
- // First build the node to get its hash code.
- _Scoped_node __node { this, std::forward<_Args>(__args)... };
- const key_type& __k = _ExtractKey{}(__node._M_node->_M_v());
- auto __res = this->_M_compute_hash_code(__hint, __k);
- auto __pos
- = _M_insert_multi_node(__res.first._M_cur, __res.second,
- __node._M_node);
- __node._M_node = nullptr;
- return __pos;
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_compute_hash_code(const_iterator __hint, const key_type& __k) const
- -> pair<const_iterator, __hash_code>
- {
- if (size() <= __small_size_threshold())
- {
- if (__hint != cend())
- {
- for (auto __it = __hint; __it != cend(); ++__it)
- if (this->_M_key_equals(__k, *__it._M_cur))
- return { __it, this->_M_hash_code(*__it._M_cur) };
- }
- for (auto __it = cbegin(); __it != __hint; ++__it)
- if (this->_M_key_equals(__k, *__it._M_cur))
- return { __it, this->_M_hash_code(*__it._M_cur) };
- }
- return { __hint, this->_M_hash_code(__k) };
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_insert_unique_node(size_type __bkt, __hash_code __code,
- __node_ptr __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(__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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_insert_multi_node(__node_ptr __hint,
- __hash_code __code, __node_ptr __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);
- const key_type& __k = _ExtractKey{}(__node->_M_v());
- size_type __bkt = _M_bucket_index(__code);
- // Find the node before an equivalent one or use hint if it exists and
- // if it is equivalent.
- __node_base_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Kt, typename _Arg, typename _NodeGenerator>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_insert_unique(_Kt&& __k, _Arg&& __v,
- const _NodeGenerator& __node_gen)
- -> pair<iterator, bool>
- {
- if (size() <= __small_size_threshold())
- for (auto __it = begin(); __it != end(); ++__it)
- if (this->_M_key_equals_tr(__k, *__it._M_cur))
- return { __it, false };
- __hash_code __code = this->_M_hash_code_tr(__k);
- size_type __bkt = _M_bucket_index(__code);
- if (size() > __small_size_threshold())
- if (__node_ptr __node = _M_find_node_tr(__bkt, __k, __code))
- return { iterator(__node), false };
- _Scoped_node __node {
- __node_builder_t::_S_build(std::forward<_Kt>(__k),
- std::forward<_Arg>(__v),
- __node_gen),
- this
- };
- auto __pos
- = _M_insert_unique_node(__bkt, __code, __node._M_node);
- __node._M_node = nullptr;
- return { __pos, true };
- }
- // Insert v unconditionally.
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- template<typename _Arg, typename _NodeGenerator>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_insert(const_iterator __hint, _Arg&& __v,
- const _NodeGenerator& __node_gen,
- false_type /* __uks */)
- -> iterator
- {
- // First allocate new node so that we don't do anything if it throws.
- _Scoped_node __node{ __node_gen(std::forward<_Arg>(__v)), this };
- // Second compute the hash code so that we don't rehash if it throws.
- auto __res = this->_M_compute_hash_code(
- __hint, _ExtractKey{}(__node._M_node->_M_v()));
- auto __pos
- = _M_insert_multi_node(__res.first._M_cur, __res.second,
- __node._M_node);
- __node._M_node = nullptr;
- return __pos;
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- erase(const_iterator __it)
- -> iterator
- {
- __node_ptr __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_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_erase(size_type __bkt, __node_base_ptr __prev_n, __node_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_erase(true_type /* __uks */, const key_type& __k)
- -> size_type
- {
- __node_base_ptr __prev_n;
- __node_ptr __n;
- std::size_t __bkt;
- if (size() <= __small_size_threshold())
- {
- __prev_n = _M_find_before_node(__k);
- if (!__prev_n)
- return 0;
- // We found a matching node, erase it.
- __n = static_cast<__node_ptr>(__prev_n->_M_nxt);
- __bkt = _M_bucket_index(*__n);
- }
- else
- {
- __hash_code __code = this->_M_hash_code(__k);
- __bkt = _M_bucket_index(__code);
- // Look for the node before the first matching node.
- __prev_n = _M_find_before_node(__bkt, __k, __code);
- if (!__prev_n)
- return 0;
- // We found a matching node, erase it.
- __n = static_cast<__node_ptr>(__prev_n->_M_nxt);
- }
- _M_erase(__bkt, __prev_n, __n);
- return 1;
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_erase(false_type /* __uks */, const key_type& __k)
- -> size_type
- {
- std::size_t __bkt;
- __node_base_ptr __prev_n;
- __node_ptr __n;
- if (size() <= __small_size_threshold())
- {
- __prev_n = _M_find_before_node(__k);
- if (!__prev_n)
- return 0;
- // We found a matching node, erase it.
- __n = static_cast<__node_ptr>(__prev_n->_M_nxt);
- __bkt = _M_bucket_index(*__n);
- }
- else
- {
- __hash_code __code = this->_M_hash_code(__k);
- __bkt = _M_bucket_index(__code);
- // Look for the node before the first matching node.
- __prev_n = _M_find_before_node(__bkt, __k, __code);
- if (!__prev_n)
- return 0;
- __n = static_cast<__node_ptr>(__prev_n->_M_nxt);
- }
- // _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_ptr __n_last = __n->_M_next();
- while (__n_last && this->_M_node_equals(*__n, *__n_last))
- __n_last = __n_last->_M_next();
- std::size_t __n_last_bkt = __n_last ? _M_bucket_index(*__n_last) : __bkt;
- // Deallocate nodes.
- size_type __result = 0;
- do
- {
- __node_ptr __p = __n->_M_next();
- this->_M_deallocate_node(__n);
- __n = __p;
- ++__result;
- }
- while (__n != __n_last);
- _M_element_count -= __result;
- if (__prev_n == _M_buckets[__bkt])
- _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt);
- else if (__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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- auto
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- erase(const_iterator __first, const_iterator __last)
- -> iterator
- {
- __node_ptr __n = __first._M_cur;
- __node_ptr __last_n = __last._M_cur;
- if (__n == __last_n)
- return iterator(__n);
- std::size_t __bkt = _M_bucket_index(*__n);
- __node_base_ptr __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_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- clear() noexcept
- {
- this->_M_deallocate_nodes(_M_begin());
- __builtin_memset(_M_buckets, 0,
- _M_bucket_count * sizeof(__node_base_ptr));
- _M_element_count = 0;
- _M_before_begin._M_nxt = nullptr;
- }
- template<typename _Key, typename _Value, typename _Alloc,
- typename _ExtractKey, typename _Equal,
- typename _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_rehash_aux(size_type __bkt_count, true_type /* __uks */)
- {
- __buckets_ptr __new_buckets = _M_allocate_buckets(__bkt_count);
- __node_ptr __p = _M_begin();
- _M_before_begin._M_nxt = nullptr;
- std::size_t __bbegin_bkt = 0;
- while (__p)
- {
- __node_ptr __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 _Hash, typename _RangeHash, typename _Unused,
- typename _RehashPolicy, typename _Traits>
- void
- _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
- _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::
- _M_rehash_aux(size_type __bkt_count, false_type /* __uks */)
- {
- __buckets_ptr __new_buckets = _M_allocate_buckets(__bkt_count);
- __node_ptr __p = _M_begin();
- _M_before_begin._M_nxt = nullptr;
- std::size_t __bbegin_bkt = 0;
- std::size_t __prev_bkt = 0;
- __node_ptr __prev_p = nullptr;
- bool __check_bucket = false;
- while (__p)
- {
- __node_ptr __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
- /// @endcond
- _GLIBCXX_END_NAMESPACE_VERSION
- } // namespace std
- #endif // _HASHTABLE_H
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