// Internal policy header for unordered_set and unordered_map -*- C++ -*- // Copyright (C) 2010-2020 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_policy.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_POLICY_H #define _HASHTABLE_POLICY_H 1 #include <tuple> // for std::tuple, std::forward_as_tuple #include <limits> // for std::numeric_limits #include <bits/stl_algobase.h> // for std::min, std::is_permutation. namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> class _Hashtable; namespace __detail { /** * @defgroup hashtable-detail Base and Implementation Classes * @ingroup unordered_associative_containers * @{ */ template<typename _Key, typename _Value, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _Traits> struct _Hashtable_base; // Helper function: return distance(first, last) for forward // iterators, or 0/1 for input iterators. template<class _Iterator> inline typename std::iterator_traits<_Iterator>::difference_type __distance_fw(_Iterator __first, _Iterator __last, std::input_iterator_tag) { return __first != __last ? 1 : 0; } template<class _Iterator> inline typename std::iterator_traits<_Iterator>::difference_type __distance_fw(_Iterator __first, _Iterator __last, std::forward_iterator_tag) { return std::distance(__first, __last); } template<class _Iterator> inline typename std::iterator_traits<_Iterator>::difference_type __distance_fw(_Iterator __first, _Iterator __last) { return __distance_fw(__first, __last, std::__iterator_category(__first)); } struct _Identity { template<typename _Tp> _Tp&& operator()(_Tp&& __x) const { return std::forward<_Tp>(__x); } }; struct _Select1st { template<typename _Tp> auto operator()(_Tp&& __x) const -> decltype(std::get<0>(std::forward<_Tp>(__x))) { return std::get<0>(std::forward<_Tp>(__x)); } }; template<typename _NodeAlloc> struct _Hashtable_alloc; // Functor recycling a pool of nodes and using allocation once the pool is // empty. template<typename _NodeAlloc> struct _ReuseOrAllocNode { private: using __node_alloc_type = _NodeAlloc; using __hashtable_alloc = _Hashtable_alloc<__node_alloc_type>; using __node_alloc_traits = typename __hashtable_alloc::__node_alloc_traits; using __node_type = typename __hashtable_alloc::__node_type; public: _ReuseOrAllocNode(__node_type* __nodes, __hashtable_alloc& __h) : _M_nodes(__nodes), _M_h(__h) { } _ReuseOrAllocNode(const _ReuseOrAllocNode&) = delete; ~_ReuseOrAllocNode() { _M_h._M_deallocate_nodes(_M_nodes); } template<typename _Arg> __node_type* operator()(_Arg&& __arg) const { if (_M_nodes) { __node_type* __node = _M_nodes; _M_nodes = _M_nodes->_M_next(); __node->_M_nxt = nullptr; auto& __a = _M_h._M_node_allocator(); __node_alloc_traits::destroy(__a, __node->_M_valptr()); __try { __node_alloc_traits::construct(__a, __node->_M_valptr(), std::forward<_Arg>(__arg)); } __catch(...) { _M_h._M_deallocate_node_ptr(__node); __throw_exception_again; } return __node; } return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); } private: mutable __node_type* _M_nodes; __hashtable_alloc& _M_h; }; // Functor similar to the previous one but without any pool of nodes to // recycle. template<typename _NodeAlloc> struct _AllocNode { private: using __hashtable_alloc = _Hashtable_alloc<_NodeAlloc>; using __node_type = typename __hashtable_alloc::__node_type; public: _AllocNode(__hashtable_alloc& __h) : _M_h(__h) { } template<typename _Arg> __node_type* operator()(_Arg&& __arg) const { return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); } private: __hashtable_alloc& _M_h; }; // Auxiliary types used for all instantiations of _Hashtable nodes // and iterators. /** * struct _Hashtable_traits * * Important traits for hash tables. * * @tparam _Cache_hash_code Boolean value. True if the value of * the hash function is stored along with the value. This is a * time-space tradeoff. Storing it may improve lookup speed by * reducing the number of times we need to call the _Hash or _Equal * functors. * * @tparam _Constant_iterators Boolean value. True if iterator and * const_iterator are both constant iterator types. This is true * for unordered_set and unordered_multiset, false for * unordered_map and unordered_multimap. * * @tparam _Unique_keys Boolean value. True if the return value * of _Hashtable::count(k) is always at most one, false if it may * be an arbitrary number. This is true for unordered_set and * unordered_map, false for unordered_multiset and * unordered_multimap. */ template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys> struct _Hashtable_traits { using __hash_cached = __bool_constant<_Cache_hash_code>; using __constant_iterators = __bool_constant<_Constant_iterators>; using __unique_keys = __bool_constant<_Unique_keys>; }; /** * struct _Hash_node_base * * Nodes, used to wrap elements stored in the hash table. A policy * template parameter of class template _Hashtable controls whether * nodes also store a hash code. In some cases (e.g. strings) this * may be a performance win. */ struct _Hash_node_base { _Hash_node_base* _M_nxt; _Hash_node_base() noexcept : _M_nxt() { } _Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { } }; /** * struct _Hash_node_value_base * * Node type with the value to store. */ template<typename _Value> struct _Hash_node_value_base : _Hash_node_base { typedef _Value value_type; __gnu_cxx::__aligned_buffer<_Value> _M_storage; _Value* _M_valptr() noexcept { return _M_storage._M_ptr(); } const _Value* _M_valptr() const noexcept { return _M_storage._M_ptr(); } _Value& _M_v() noexcept { return *_M_valptr(); } const _Value& _M_v() const noexcept { return *_M_valptr(); } }; /** * Primary template struct _Hash_node. */ template<typename _Value, bool _Cache_hash_code> struct _Hash_node; /** * Specialization for nodes with caches, struct _Hash_node. * * Base class is __detail::_Hash_node_value_base. */ template<typename _Value> struct _Hash_node<_Value, true> : _Hash_node_value_base<_Value> { std::size_t _M_hash_code; _Hash_node* _M_next() const noexcept { return static_cast<_Hash_node*>(this->_M_nxt); } }; /** * Specialization for nodes without caches, struct _Hash_node. * * Base class is __detail::_Hash_node_value_base. */ template<typename _Value> struct _Hash_node<_Value, false> : _Hash_node_value_base<_Value> { _Hash_node* _M_next() const noexcept { return static_cast<_Hash_node*>(this->_M_nxt); } }; /// Base class for node iterators. template<typename _Value, bool _Cache_hash_code> struct _Node_iterator_base { using __node_type = _Hash_node<_Value, _Cache_hash_code>; __node_type* _M_cur; _Node_iterator_base(__node_type* __p) noexcept : _M_cur(__p) { } void _M_incr() noexcept { _M_cur = _M_cur->_M_next(); } }; template<typename _Value, bool _Cache_hash_code> inline bool operator==(const _Node_iterator_base<_Value, _Cache_hash_code>& __x, const _Node_iterator_base<_Value, _Cache_hash_code >& __y) noexcept { return __x._M_cur == __y._M_cur; } template<typename _Value, bool _Cache_hash_code> inline bool operator!=(const _Node_iterator_base<_Value, _Cache_hash_code>& __x, const _Node_iterator_base<_Value, _Cache_hash_code>& __y) noexcept { return __x._M_cur != __y._M_cur; } /// Node iterators, used to iterate through all the hashtable. template<typename _Value, bool __constant_iterators, bool __cache> struct _Node_iterator : public _Node_iterator_base<_Value, __cache> { private: using __base_type = _Node_iterator_base<_Value, __cache>; using __node_type = typename __base_type::__node_type; public: typedef _Value value_type; typedef std::ptrdiff_t difference_type; typedef std::forward_iterator_tag iterator_category; using pointer = typename std::conditional<__constant_iterators, const _Value*, _Value*>::type; using reference = typename std::conditional<__constant_iterators, const _Value&, _Value&>::type; _Node_iterator() noexcept : __base_type(0) { } explicit _Node_iterator(__node_type* __p) noexcept : __base_type(__p) { } reference operator*() const noexcept { return this->_M_cur->_M_v(); } pointer operator->() const noexcept { return this->_M_cur->_M_valptr(); } _Node_iterator& operator++() noexcept { this->_M_incr(); return *this; } _Node_iterator operator++(int) noexcept { _Node_iterator __tmp(*this); this->_M_incr(); return __tmp; } }; /// Node const_iterators, used to iterate through all the hashtable. template<typename _Value, bool __constant_iterators, bool __cache> struct _Node_const_iterator : public _Node_iterator_base<_Value, __cache> { private: using __base_type = _Node_iterator_base<_Value, __cache>; using __node_type = typename __base_type::__node_type; public: typedef _Value value_type; typedef std::ptrdiff_t difference_type; typedef std::forward_iterator_tag iterator_category; typedef const _Value* pointer; typedef const _Value& reference; _Node_const_iterator() noexcept : __base_type(0) { } explicit _Node_const_iterator(__node_type* __p) noexcept : __base_type(__p) { } _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators, __cache>& __x) noexcept : __base_type(__x._M_cur) { } reference operator*() const noexcept { return this->_M_cur->_M_v(); } pointer operator->() const noexcept { return this->_M_cur->_M_valptr(); } _Node_const_iterator& operator++() noexcept { this->_M_incr(); return *this; } _Node_const_iterator operator++(int) noexcept { _Node_const_iterator __tmp(*this); this->_M_incr(); return __tmp; } }; // Many of class template _Hashtable's template parameters are policy // classes. These are defaults for the policies. /// Default range hashing function: use division to fold a large number /// into the range [0, N). struct _Mod_range_hashing { typedef std::size_t first_argument_type; typedef std::size_t second_argument_type; typedef std::size_t result_type; result_type operator()(first_argument_type __num, second_argument_type __den) const noexcept { return __num % __den; } }; /// Default ranged hash function H. In principle it should be a /// function object composed from objects of type H1 and H2 such that /// h(k, N) = h2(h1(k), N), but that would mean making extra copies of /// h1 and h2. So instead we'll just use a tag to tell class template /// hashtable to do that composition. struct _Default_ranged_hash { }; /// Default value for rehash policy. Bucket size is (usually) the /// smallest prime that keeps the load factor small enough. struct _Prime_rehash_policy { using __has_load_factor = true_type; _Prime_rehash_policy(float __z = 1.0) noexcept : _M_max_load_factor(__z), _M_next_resize(0) { } float max_load_factor() const noexcept { return _M_max_load_factor; } // Return a bucket size no smaller than n. std::size_t _M_next_bkt(std::size_t __n) const; // Return a bucket count appropriate for n elements std::size_t _M_bkt_for_elements(std::size_t __n) const { return __builtin_ceill(__n / (long double)_M_max_load_factor); } // __n_bkt is current bucket count, __n_elt is current element count, // and __n_ins is number of elements to be inserted. Do we need to // increase bucket count? If so, return make_pair(true, n), where n // is the new bucket count. If not, return make_pair(false, 0). std::pair<bool, std::size_t> _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, std::size_t __n_ins) const; typedef std::size_t _State; _State _M_state() const { return _M_next_resize; } void _M_reset() noexcept { _M_next_resize = 0; } void _M_reset(_State __state) { _M_next_resize = __state; } static const std::size_t _S_growth_factor = 2; float _M_max_load_factor; mutable std::size_t _M_next_resize; }; /// Range hashing function assuming that second arg is a power of 2. struct _Mask_range_hashing { typedef std::size_t first_argument_type; typedef std::size_t second_argument_type; typedef std::size_t result_type; result_type operator()(first_argument_type __num, second_argument_type __den) const noexcept { return __num & (__den - 1); } }; /// Compute closest power of 2 not less than __n inline std::size_t __clp2(std::size_t __n) noexcept { // Equivalent to return __n ? std::bit_ceil(__n) : 0; if (__n < 2) return __n; const unsigned __lz = sizeof(size_t) > sizeof(long) ? __builtin_clzll(__n - 1ull) : __builtin_clzl(__n - 1ul); // Doing two shifts avoids undefined behaviour when __lz == 0. return (size_t(1) << (numeric_limits<size_t>::digits - __lz - 1)) << 1; } /// Rehash policy providing power of 2 bucket numbers. Avoids modulo /// operations. struct _Power2_rehash_policy { using __has_load_factor = true_type; _Power2_rehash_policy(float __z = 1.0) noexcept : _M_max_load_factor(__z), _M_next_resize(0) { } float max_load_factor() const noexcept { return _M_max_load_factor; } // Return a bucket size no smaller than n (as long as n is not above the // highest power of 2). std::size_t _M_next_bkt(std::size_t __n) noexcept { if (__n == 0) // Special case on container 1st initialization with 0 bucket count // hint. We keep _M_next_resize to 0 to make sure that next time we // want to add an element allocation will take place. return 1; const auto __max_width = std::min<size_t>(sizeof(size_t), 8); const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1); std::size_t __res = __clp2(__n); if (__res == 0) __res = __max_bkt; else if (__res == 1) // If __res is 1 we force it to 2 to make sure there will be an // allocation so that nothing need to be stored in the initial // single bucket __res = 2; if (__res == __max_bkt) // Set next resize to the max value so that we never try to rehash again // as we already reach the biggest possible bucket number. // Note that it might result in max_load_factor not being respected. _M_next_resize = numeric_limits<size_t>::max(); else _M_next_resize = __builtin_floorl(__res * (long double)_M_max_load_factor); return __res; } // Return a bucket count appropriate for n elements std::size_t _M_bkt_for_elements(std::size_t __n) const noexcept { return __builtin_ceill(__n / (long double)_M_max_load_factor); } // __n_bkt is current bucket count, __n_elt is current element count, // and __n_ins is number of elements to be inserted. Do we need to // increase bucket count? If so, return make_pair(true, n), where n // is the new bucket count. If not, return make_pair(false, 0). std::pair<bool, std::size_t> _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, std::size_t __n_ins) noexcept { if (__n_elt + __n_ins > _M_next_resize) { // If _M_next_resize is 0 it means that we have nothing allocated so // far and that we start inserting elements. In this case we start // with an initial bucket size of 11. long double __min_bkts = std::max<std::size_t>(__n_elt + __n_ins, _M_next_resize ? 0 : 11) / (long double)_M_max_load_factor; if (__min_bkts >= __n_bkt) return { true, _M_next_bkt(std::max<std::size_t>(__builtin_floorl(__min_bkts) + 1, __n_bkt * _S_growth_factor)) }; _M_next_resize = __builtin_floorl(__n_bkt * (long double)_M_max_load_factor); return { false, 0 }; } else return { false, 0 }; } typedef std::size_t _State; _State _M_state() const noexcept { return _M_next_resize; } void _M_reset() noexcept { _M_next_resize = 0; } void _M_reset(_State __state) noexcept { _M_next_resize = __state; } static const std::size_t _S_growth_factor = 2; float _M_max_load_factor; std::size_t _M_next_resize; }; // Base classes for std::_Hashtable. We define these base classes // because in some cases we want to do different things depending on // the value of a policy class. In some cases the policy class // affects which member functions and nested typedefs are defined; // we handle that by specializing base class templates. Several of // the base class templates need to access other members of class // template _Hashtable, so we use a variant of the "Curiously // Recurring Template Pattern" (CRTP) technique. /** * Primary class template _Map_base. * * If the hashtable has a value type of the form pair<T1, T2> and a * key extraction policy (_ExtractKey) that returns the first part * of the pair, the hashtable gets a mapped_type typedef. If it * satisfies those criteria and also has unique keys, then it also * gets an operator[]. */ template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits, bool _Unique_keys = _Traits::__unique_keys::value> struct _Map_base { }; /// Partial specialization, __unique_keys set to false. template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, false> { using mapped_type = typename std::tuple_element<1, _Pair>::type; }; /// Partial specialization, __unique_keys set to true. template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true> { private: using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair, _Select1st, _Equal, _H1, _H2, _Hash, _Traits>; using __hashtable = _Hashtable<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using __hash_code = typename __hashtable_base::__hash_code; using __node_type = typename __hashtable_base::__node_type; public: using key_type = typename __hashtable_base::key_type; using iterator = typename __hashtable_base::iterator; using mapped_type = typename std::tuple_element<1, _Pair>::type; mapped_type& operator[](const key_type& __k); mapped_type& operator[](key_type&& __k); // _GLIBCXX_RESOLVE_LIB_DEFECTS // DR 761. unordered_map needs an at() member function. mapped_type& at(const key_type& __k); const mapped_type& at(const key_type& __k) const; }; template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: operator[](const key_type& __k) -> mapped_type& { __hashtable* __h = static_cast<__hashtable*>(this); __hash_code __code = __h->_M_hash_code(__k); std::size_t __bkt = __h->_M_bucket_index(__k, __code); if (__node_type* __node = __h->_M_find_node(__bkt, __k, __code)) return __node->_M_v().second; typename __hashtable::_Scoped_node __node { __h, std::piecewise_construct, std::tuple<const key_type&>(__k), std::tuple<>() }; auto __pos = __h->_M_insert_unique_node(__k, __bkt, __code, __node._M_node); __node._M_node = nullptr; return __pos->second; } template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: operator[](key_type&& __k) -> mapped_type& { __hashtable* __h = static_cast<__hashtable*>(this); __hash_code __code = __h->_M_hash_code(__k); std::size_t __bkt = __h->_M_bucket_index(__k, __code); if (__node_type* __node = __h->_M_find_node(__bkt, __k, __code)) return __node->_M_v().second; typename __hashtable::_Scoped_node __node { __h, std::piecewise_construct, std::forward_as_tuple(std::move(__k)), std::tuple<>() }; auto __pos = __h->_M_insert_unique_node(__k, __bkt, __code, __node._M_node); __node._M_node = nullptr; return __pos->second; } template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: at(const key_type& __k) -> mapped_type& { __hashtable* __h = static_cast<__hashtable*>(this); __hash_code __code = __h->_M_hash_code(__k); std::size_t __bkt = __h->_M_bucket_index(__k, __code); __node_type* __p = __h->_M_find_node(__bkt, __k, __code); if (!__p) __throw_out_of_range(__N("_Map_base::at")); return __p->_M_v().second; } template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> auto _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: at(const key_type& __k) const -> const mapped_type& { const __hashtable* __h = static_cast<const __hashtable*>(this); __hash_code __code = __h->_M_hash_code(__k); std::size_t __bkt = __h->_M_bucket_index(__k, __code); __node_type* __p = __h->_M_find_node(__bkt, __k, __code); if (!__p) __throw_out_of_range(__N("_Map_base::at")); return __p->_M_v().second; } /** * Primary class template _Insert_base. * * Defines @c insert member functions appropriate to all _Hashtables. */ template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Insert_base { protected: using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>; using value_type = typename __hashtable_base::value_type; using iterator = typename __hashtable_base::iterator; using const_iterator = typename __hashtable_base::const_iterator; using size_type = typename __hashtable_base::size_type; using __unique_keys = typename __hashtable_base::__unique_keys; using __ireturn_type = typename __hashtable_base::__ireturn_type; using __node_type = _Hash_node<_Value, _Traits::__hash_cached::value>; using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>; using __node_gen_type = _AllocNode<__node_alloc_type>; __hashtable& _M_conjure_hashtable() { return *(static_cast<__hashtable*>(this)); } template<typename _InputIterator, typename _NodeGetter> void _M_insert_range(_InputIterator __first, _InputIterator __last, const _NodeGetter&, true_type); template<typename _InputIterator, typename _NodeGetter> void _M_insert_range(_InputIterator __first, _InputIterator __last, const _NodeGetter&, false_type); public: __ireturn_type insert(const value_type& __v) { __hashtable& __h = _M_conjure_hashtable(); __node_gen_type __node_gen(__h); return __h._M_insert(__v, __node_gen, __unique_keys()); } iterator insert(const_iterator __hint, const value_type& __v) { __hashtable& __h = _M_conjure_hashtable(); __node_gen_type __node_gen(__h); return __h._M_insert(__hint, __v, __node_gen, __unique_keys()); } void insert(initializer_list<value_type> __l) { this->insert(__l.begin(), __l.end()); } template<typename _InputIterator> void insert(_InputIterator __first, _InputIterator __last) { __hashtable& __h = _M_conjure_hashtable(); __node_gen_type __node_gen(__h); return _M_insert_range(__first, __last, __node_gen, __unique_keys()); } }; template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _InputIterator, typename _NodeGetter> void _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert_range(_InputIterator __first, _InputIterator __last, const _NodeGetter& __node_gen, true_type) { size_type __n_elt = __detail::__distance_fw(__first, __last); if (__n_elt == 0) return; __hashtable& __h = _M_conjure_hashtable(); for (; __first != __last; ++__first) { if (__h._M_insert(*__first, __node_gen, __unique_keys(), __n_elt).second) __n_elt = 1; else if (__n_elt != 1) --__n_elt; } } template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> template<typename _InputIterator, typename _NodeGetter> void _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>:: _M_insert_range(_InputIterator __first, _InputIterator __last, const _NodeGetter& __node_gen, false_type) { using __rehash_type = typename __hashtable::__rehash_type; using __rehash_state = typename __hashtable::__rehash_state; using pair_type = std::pair<bool, std::size_t>; size_type __n_elt = __detail::__distance_fw(__first, __last); if (__n_elt == 0) return; __hashtable& __h = _M_conjure_hashtable(); __rehash_type& __rehash = __h._M_rehash_policy; const __rehash_state& __saved_state = __rehash._M_state(); pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count, __h._M_element_count, __n_elt); if (__do_rehash.first) __h._M_rehash(__do_rehash.second, __saved_state); for (; __first != __last; ++__first) __h._M_insert(*__first, __node_gen, __unique_keys()); } /** * Primary class template _Insert. * * Defines @c insert member functions that depend on _Hashtable policies, * via partial specializations. */ template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits, bool _Constant_iterators = _Traits::__constant_iterators::value> struct _Insert; /// Specialization. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true> : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits> { using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>; using value_type = typename __base_type::value_type; using iterator = typename __base_type::iterator; using const_iterator = typename __base_type::const_iterator; using __unique_keys = typename __base_type::__unique_keys; using __ireturn_type = typename __hashtable_base::__ireturn_type; using __hashtable = typename __base_type::__hashtable; using __node_gen_type = typename __base_type::__node_gen_type; using __base_type::insert; __ireturn_type insert(value_type&& __v) { __hashtable& __h = this->_M_conjure_hashtable(); __node_gen_type __node_gen(__h); return __h._M_insert(std::move(__v), __node_gen, __unique_keys()); } iterator insert(const_iterator __hint, value_type&& __v) { __hashtable& __h = this->_M_conjure_hashtable(); __node_gen_type __node_gen(__h); return __h._M_insert(__hint, std::move(__v), __node_gen, __unique_keys()); } }; /// Specialization. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, false> : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits> { using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; using value_type = typename __base_type::value_type; using iterator = typename __base_type::iterator; using const_iterator = typename __base_type::const_iterator; using __unique_keys = typename __base_type::__unique_keys; using __hashtable = typename __base_type::__hashtable; using __ireturn_type = typename __base_type::__ireturn_type; using __base_type::insert; template<typename _Pair> using __is_cons = std::is_constructible<value_type, _Pair&&>; template<typename _Pair> using _IFcons = std::enable_if<__is_cons<_Pair>::value>; template<typename _Pair> using _IFconsp = typename _IFcons<_Pair>::type; template<typename _Pair, typename = _IFconsp<_Pair>> __ireturn_type insert(_Pair&& __v) { __hashtable& __h = this->_M_conjure_hashtable(); return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v)); } template<typename _Pair, typename = _IFconsp<_Pair>> iterator insert(const_iterator __hint, _Pair&& __v) { __hashtable& __h = this->_M_conjure_hashtable(); return __h._M_emplace(__hint, __unique_keys(), std::forward<_Pair>(__v)); } }; template<typename _Policy> using __has_load_factor = typename _Policy::__has_load_factor; /** * Primary class template _Rehash_base. * * Give hashtable the max_load_factor functions and reserve iff the * rehash policy supports it. */ template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits, typename = __detected_or_t<false_type, __has_load_factor, _RehashPolicy>> struct _Rehash_base; /// Specialization when rehash policy doesn't provide load factor management. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, false_type> { }; /// Specialization when rehash policy provide load factor management. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true_type> { using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; float max_load_factor() const noexcept { const __hashtable* __this = static_cast<const __hashtable*>(this); return __this->__rehash_policy().max_load_factor(); } void max_load_factor(float __z) { __hashtable* __this = static_cast<__hashtable*>(this); __this->__rehash_policy(_RehashPolicy(__z)); } void reserve(std::size_t __n) { __hashtable* __this = static_cast<__hashtable*>(this); __this->rehash(__this->__rehash_policy()._M_bkt_for_elements(__n)); } }; /** * Primary class template _Hashtable_ebo_helper. * * Helper class using EBO when it is not forbidden (the type is not * final) and when it is worth it (the type is empty.) */ template<int _Nm, typename _Tp, bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)> struct _Hashtable_ebo_helper; /// Specialization using EBO. template<int _Nm, typename _Tp> struct _Hashtable_ebo_helper<_Nm, _Tp, true> : private _Tp { _Hashtable_ebo_helper() = default; template<typename _OtherTp> _Hashtable_ebo_helper(_OtherTp&& __tp) : _Tp(std::forward<_OtherTp>(__tp)) { } const _Tp& _M_cget() const { return static_cast<const _Tp&>(*this); } _Tp& _M_get() { return static_cast<_Tp&>(*this); } }; /// Specialization not using EBO. template<int _Nm, typename _Tp> struct _Hashtable_ebo_helper<_Nm, _Tp, false> { _Hashtable_ebo_helper() = default; template<typename _OtherTp> _Hashtable_ebo_helper(_OtherTp&& __tp) : _M_tp(std::forward<_OtherTp>(__tp)) { } const _Tp& _M_cget() const { return _M_tp; } _Tp& _M_get() { return _M_tp; } private: _Tp _M_tp; }; /** * Primary class template _Local_iterator_base. * * Base class for local iterators, used to iterate within a bucket * but not between buckets. */ template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash, bool __cache_hash_code> struct _Local_iterator_base; /** * Primary class template _Hash_code_base. * * Encapsulates two policy issues that aren't quite orthogonal. * (1) the difference between using a ranged hash function and using * the combination of a hash function and a range-hashing function. * In the former case we don't have such things as hash codes, so * we have a dummy type as placeholder. * (2) Whether or not we cache hash codes. Caching hash codes is * meaningless if we have a ranged hash function. * * We also put the key extraction objects here, for convenience. * Each specialization derives from one or more of the template * parameters to benefit from Ebo. This is important as this type * is inherited in some cases by the _Local_iterator_base type used * to implement local_iterator and const_local_iterator. As with * any iterator type we prefer to make it as small as possible. * * Primary template is unused except as a hook for specializations. */ template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash, bool __cache_hash_code> struct _Hash_code_base; /// Specialization: ranged hash function, no caching hash codes. H1 /// and H2 are provided but ignored. We define a dummy hash code type. template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash> struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false> : private _Hashtable_ebo_helper<0, _ExtractKey>, private _Hashtable_ebo_helper<1, _Hash> { private: using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>; protected: typedef void* __hash_code; typedef _Hash_node<_Value, false> __node_type; // We need the default constructor for the local iterators and _Hashtable // default constructor. _Hash_code_base() = default; _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&, const _Hash& __h) : __ebo_extract_key(__ex), __ebo_hash(__h) { } __hash_code _M_hash_code(const _Key& __key) const { return 0; } std::size_t _M_bucket_index(const _Key& __k, __hash_code, std::size_t __bkt_count) const { return _M_ranged_hash()(__k, __bkt_count); } std::size_t _M_bucket_index(const __node_type* __p, std::size_t __bkt_count) const noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>(), (std::size_t)0)) ) { return _M_ranged_hash()(_M_extract()(__p->_M_v()), __bkt_count); } void _M_store_code(__node_type*, __hash_code) const { } void _M_copy_code(__node_type*, const __node_type*) const { } void _M_swap(_Hash_code_base& __x) { std::swap(__ebo_extract_key::_M_get(), __x.__ebo_extract_key::_M_get()); std::swap(__ebo_hash::_M_get(), __x.__ebo_hash::_M_get()); } const _ExtractKey& _M_extract() const { return __ebo_extract_key::_M_cget(); } const _Hash& _M_ranged_hash() const { return __ebo_hash::_M_cget(); } }; // No specialization for ranged hash function while caching hash codes. // That combination is meaningless, and trying to do it is an error. /// Specialization: ranged hash function, cache hash codes. This /// combination is meaningless, so we provide only a declaration /// and no definition. template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash> struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>; /// Specialization: hash function and range-hashing function, no /// caching of hash codes. /// Provides typedef and accessor required by C++ 11. template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2> struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Default_ranged_hash, false> : private _Hashtable_ebo_helper<0, _ExtractKey>, private _Hashtable_ebo_helper<1, _H1>, private _Hashtable_ebo_helper<2, _H2> { private: using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>; using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>; // Gives the local iterator implementation access to _M_bucket_index(). friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Default_ranged_hash, false>; public: typedef _H1 hasher; hasher hash_function() const { return _M_h1(); } protected: typedef std::size_t __hash_code; typedef _Hash_node<_Value, false> __node_type; // We need the default constructor for the local iterators and _Hashtable // default constructor. _Hash_code_base() = default; _Hash_code_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2, const _Default_ranged_hash&) : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { } __hash_code _M_hash_code(const _Key& __k) const { static_assert(__is_invocable<const _H1&, const _Key&>{}, "hash function must be invocable with an argument of key type"); return _M_h1()(__k); } std::size_t _M_bucket_index(const _Key&, __hash_code __c, std::size_t __bkt_count) const { return _M_h2()(__c, __bkt_count); } std::size_t _M_bucket_index(const __node_type* __p, std::size_t __bkt_count) const noexcept( noexcept(declval<const _H1&>()(declval<const _Key&>())) && noexcept(declval<const _H2&>()((__hash_code)0, (std::size_t)0)) ) { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v())), __bkt_count); } void _M_store_code(__node_type*, __hash_code) const { } void _M_copy_code(__node_type*, const __node_type*) const { } void _M_swap(_Hash_code_base& __x) { std::swap(__ebo_extract_key::_M_get(), __x.__ebo_extract_key::_M_get()); std::swap(__ebo_h1::_M_get(), __x.__ebo_h1::_M_get()); std::swap(__ebo_h2::_M_get(), __x.__ebo_h2::_M_get()); } const _ExtractKey& _M_extract() const { return __ebo_extract_key::_M_cget(); } const _H1& _M_h1() const { return __ebo_h1::_M_cget(); } const _H2& _M_h2() const { return __ebo_h2::_M_cget(); } }; /// Specialization: hash function and range-hashing function, /// caching hash codes. H is provided but ignored. Provides /// typedef and accessor required by C++ 11. template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2> struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Default_ranged_hash, true> : private _Hashtable_ebo_helper<0, _ExtractKey>, private _Hashtable_ebo_helper<1, _H1>, private _Hashtable_ebo_helper<2, _H2> { private: // Gives the local iterator implementation access to _M_h2(). friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Default_ranged_hash, true>; using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>; using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>; public: typedef _H1 hasher; hasher hash_function() const { return _M_h1(); } protected: typedef std::size_t __hash_code; typedef _Hash_node<_Value, true> __node_type; // We need the default constructor for _Hashtable default constructor. _Hash_code_base() = default; _Hash_code_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2, const _Default_ranged_hash&) : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { } __hash_code _M_hash_code(const _Key& __k) const { static_assert(__is_invocable<const _H1&, const _Key&>{}, "hash function must be invocable with an argument of key type"); return _M_h1()(__k); } std::size_t _M_bucket_index(const _Key&, __hash_code __c, std::size_t __bkt_count) const { return _M_h2()(__c, __bkt_count); } std::size_t _M_bucket_index(const __node_type* __p, std::size_t __bkt_count) const noexcept( noexcept(declval<const _H2&>()((__hash_code)0, (std::size_t)0)) ) { return _M_h2()(__p->_M_hash_code, __bkt_count); } void _M_store_code(__node_type* __n, __hash_code __c) const { __n->_M_hash_code = __c; } void _M_copy_code(__node_type* __to, const __node_type* __from) const { __to->_M_hash_code = __from->_M_hash_code; } void _M_swap(_Hash_code_base& __x) { std::swap(__ebo_extract_key::_M_get(), __x.__ebo_extract_key::_M_get()); std::swap(__ebo_h1::_M_get(), __x.__ebo_h1::_M_get()); std::swap(__ebo_h2::_M_get(), __x.__ebo_h2::_M_get()); } const _ExtractKey& _M_extract() const { return __ebo_extract_key::_M_cget(); } const _H1& _M_h1() const { return __ebo_h1::_M_cget(); } const _H2& _M_h2() const { return __ebo_h2::_M_cget(); } }; /// Partial specialization used when nodes contain a cached hash code. template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash> struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true> : private _Hashtable_ebo_helper<0, _H2> { protected: using __base_type = _Hashtable_ebo_helper<0, _H2>; using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>; _Local_iterator_base() = default; _Local_iterator_base(const __hash_code_base& __base, _Hash_node<_Value, true>* __p, std::size_t __bkt, std::size_t __bkt_count) : __base_type(__base._M_h2()), _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { } void _M_incr() { _M_cur = _M_cur->_M_next(); if (_M_cur) { std::size_t __bkt = __base_type::_M_get()(_M_cur->_M_hash_code, _M_bucket_count); if (__bkt != _M_bucket) _M_cur = nullptr; } } _Hash_node<_Value, true>* _M_cur; std::size_t _M_bucket; std::size_t _M_bucket_count; public: const void* _M_curr() const { return _M_cur; } // for equality ops std::size_t _M_get_bucket() const { return _M_bucket; } // for debug mode }; // Uninitialized storage for a _Hash_code_base. // This type is DefaultConstructible and Assignable even if the // _Hash_code_base type isn't, so that _Local_iterator_base<..., false> // can be DefaultConstructible and Assignable. template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value> struct _Hash_code_storage { __gnu_cxx::__aligned_buffer<_Tp> _M_storage; _Tp* _M_h() { return _M_storage._M_ptr(); } const _Tp* _M_h() const { return _M_storage._M_ptr(); } }; // Empty partial specialization for empty _Hash_code_base types. template<typename _Tp> struct _Hash_code_storage<_Tp, true> { static_assert( std::is_empty<_Tp>::value, "Type must be empty" ); // As _Tp is an empty type there will be no bytes written/read through // the cast pointer, so no strict-aliasing violation. _Tp* _M_h() { return reinterpret_cast<_Tp*>(this); } const _Tp* _M_h() const { return reinterpret_cast<const _Tp*>(this); } }; template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash> using __hash_code_for_local_iter = _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>>; // Partial specialization used when hash codes are not cached template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash> struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false> : __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _H1, _H2, _Hash> { protected: using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>; _Local_iterator_base() : _M_bucket_count(-1) { } _Local_iterator_base(const __hash_code_base& __base, _Hash_node<_Value, false>* __p, std::size_t __bkt, std::size_t __bkt_count) : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { _M_init(__base); } ~_Local_iterator_base() { if (_M_bucket_count != -1) _M_destroy(); } _Local_iterator_base(const _Local_iterator_base& __iter) : _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket), _M_bucket_count(__iter._M_bucket_count) { if (_M_bucket_count != -1) _M_init(*__iter._M_h()); } _Local_iterator_base& operator=(const _Local_iterator_base& __iter) { if (_M_bucket_count != -1) _M_destroy(); _M_cur = __iter._M_cur; _M_bucket = __iter._M_bucket; _M_bucket_count = __iter._M_bucket_count; if (_M_bucket_count != -1) _M_init(*__iter._M_h()); return *this; } void _M_incr() { _M_cur = _M_cur->_M_next(); if (_M_cur) { std::size_t __bkt = this->_M_h()->_M_bucket_index(_M_cur, _M_bucket_count); if (__bkt != _M_bucket) _M_cur = nullptr; } } _Hash_node<_Value, false>* _M_cur; std::size_t _M_bucket; std::size_t _M_bucket_count; void _M_init(const __hash_code_base& __base) { ::new(this->_M_h()) __hash_code_base(__base); } void _M_destroy() { this->_M_h()->~__hash_code_base(); } public: const void* _M_curr() const { return _M_cur; } // for equality ops and debug mode std::size_t _M_get_bucket() const { return _M_bucket; } // for debug mode }; template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash, bool __cache> inline bool operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache>& __x, const _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache>& __y) { return __x._M_curr() == __y._M_curr(); } template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash, bool __cache> inline bool operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache>& __x, const _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache>& __y) { return __x._M_curr() != __y._M_curr(); } /// local iterators template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash, bool __constant_iterators, bool __cache> struct _Local_iterator : public _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache> { private: using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache>; using __hash_code_base = typename __base_type::__hash_code_base; public: typedef _Value value_type; typedef typename std::conditional<__constant_iterators, const _Value*, _Value*>::type pointer; typedef typename std::conditional<__constant_iterators, const _Value&, _Value&>::type reference; typedef std::ptrdiff_t difference_type; typedef std::forward_iterator_tag iterator_category; _Local_iterator() = default; _Local_iterator(const __hash_code_base& __base, _Hash_node<_Value, __cache>* __n, std::size_t __bkt, std::size_t __bkt_count) : __base_type(__base, __n, __bkt, __bkt_count) { } reference operator*() const { return this->_M_cur->_M_v(); } pointer operator->() const { return this->_M_cur->_M_valptr(); } _Local_iterator& operator++() { this->_M_incr(); return *this; } _Local_iterator operator++(int) { _Local_iterator __tmp(*this); this->_M_incr(); return __tmp; } }; /// local const_iterators template<typename _Key, typename _Value, typename _ExtractKey, typename _H1, typename _H2, typename _Hash, bool __constant_iterators, bool __cache> struct _Local_const_iterator : public _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache> { private: using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __cache>; using __hash_code_base = typename __base_type::__hash_code_base; public: typedef _Value value_type; typedef const _Value* pointer; typedef const _Value& reference; typedef std::ptrdiff_t difference_type; typedef std::forward_iterator_tag iterator_category; _Local_const_iterator() = default; _Local_const_iterator(const __hash_code_base& __base, _Hash_node<_Value, __cache>* __n, std::size_t __bkt, std::size_t __bkt_count) : __base_type(__base, __n, __bkt, __bkt_count) { } _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __constant_iterators, __cache>& __x) : __base_type(__x) { } reference operator*() const { return this->_M_cur->_M_v(); } pointer operator->() const { return this->_M_cur->_M_valptr(); } _Local_const_iterator& operator++() { this->_M_incr(); return *this; } _Local_const_iterator operator++(int) { _Local_const_iterator __tmp(*this); this->_M_incr(); return __tmp; } }; /** * Primary class template _Hashtable_base. * * Helper class adding management of _Equal functor to * _Hash_code_base type. * * Base class templates are: * - __detail::_Hash_code_base * - __detail::_Hashtable_ebo_helper */ template<typename _Key, typename _Value, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _Traits> struct _Hashtable_base : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, _Traits::__hash_cached::value>, private _Hashtable_ebo_helper<0, _Equal> { public: typedef _Key key_type; typedef _Value value_type; typedef _Equal key_equal; typedef std::size_t size_type; typedef std::ptrdiff_t difference_type; using __traits_type = _Traits; using __hash_cached = typename __traits_type::__hash_cached; using __constant_iterators = typename __traits_type::__constant_iterators; using __unique_keys = typename __traits_type::__unique_keys; using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, __hash_cached::value>; using __hash_code = typename __hash_code_base::__hash_code; using __node_type = typename __hash_code_base::__node_type; using iterator = __detail::_Node_iterator<value_type, __constant_iterators::value, __hash_cached::value>; using const_iterator = __detail::_Node_const_iterator<value_type, __constant_iterators::value, __hash_cached::value>; using local_iterator = __detail::_Local_iterator<key_type, value_type, _ExtractKey, _H1, _H2, _Hash, __constant_iterators::value, __hash_cached::value>; using const_local_iterator = __detail::_Local_const_iterator<key_type, value_type, _ExtractKey, _H1, _H2, _Hash, __constant_iterators::value, __hash_cached::value>; using __ireturn_type = typename std::conditional<__unique_keys::value, std::pair<iterator, bool>, iterator>::type; private: using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>; template<typename _NodeT> struct _Equal_hash_code { static bool _S_equals(__hash_code, const _NodeT&) { return true; } }; template<typename _Ptr2> struct _Equal_hash_code<_Hash_node<_Ptr2, true>> { static bool _S_equals(__hash_code __c, const _Hash_node<_Ptr2, true>& __n) { return __c == __n._M_hash_code; } }; protected: _Hashtable_base() = default; _Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2, const _Hash& __hash, const _Equal& __eq) : __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq) { } bool _M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const { static_assert(__is_invocable<const _Equal&, const _Key&, const _Key&>{}, "key equality predicate must be invocable with two arguments of " "key type"); return _Equal_hash_code<__node_type>::_S_equals(__c, *__n) && _M_eq()(__k, this->_M_extract()(__n->_M_v())); } void _M_swap(_Hashtable_base& __x) { __hash_code_base::_M_swap(__x); std::swap(_EqualEBO::_M_get(), __x._EqualEBO::_M_get()); } const _Equal& _M_eq() const { return _EqualEBO::_M_cget(); } }; /** * Primary class template _Equality. * * This is for implementing equality comparison for unordered * containers, per N3068, by John Lakos and Pablo Halpern. * Algorithmically, we follow closely the reference implementations * therein. */ template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits, bool _Unique_keys = _Traits::__unique_keys::value> struct _Equality; /// unordered_map and unordered_set specializations. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true> { using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; bool _M_equal(const __hashtable&) const; }; template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> bool _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: _M_equal(const __hashtable& __other) const { using __node_base = typename __hashtable::__node_base; using __node_type = typename __hashtable::__node_type; const __hashtable* __this = static_cast<const __hashtable*>(this); if (__this->size() != __other.size()) return false; for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx) { std::size_t __ybkt = __other._M_bucket_index(__itx._M_cur); __node_base* __prev_n = __other._M_buckets[__ybkt]; if (!__prev_n) return false; for (__node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);; __n = __n->_M_next()) { if (__n->_M_v() == *__itx) break; if (!__n->_M_nxt || __other._M_bucket_index(__n->_M_next()) != __ybkt) return false; } } return true; } /// unordered_multiset and unordered_multimap specializations. template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, false> { using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>; bool _M_equal(const __hashtable&) const; }; template<typename _Key, typename _Value, typename _Alloc, typename _ExtractKey, typename _Equal, typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, typename _Traits> bool _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits, false>:: _M_equal(const __hashtable& __other) const { using __node_base = typename __hashtable::__node_base; using __node_type = typename __hashtable::__node_type; const __hashtable* __this = static_cast<const __hashtable*>(this); if (__this->size() != __other.size()) return false; for (auto __itx = __this->begin(); __itx != __this->end();) { std::size_t __x_count = 1; auto __itx_end = __itx; for (++__itx_end; __itx_end != __this->end() && __this->key_eq()(_ExtractKey()(*__itx), _ExtractKey()(*__itx_end)); ++__itx_end) ++__x_count; std::size_t __ybkt = __other._M_bucket_index(__itx._M_cur); __node_base* __y_prev_n = __other._M_buckets[__ybkt]; if (!__y_prev_n) return false; __node_type* __y_n = static_cast<__node_type*>(__y_prev_n->_M_nxt); for (;; __y_n = __y_n->_M_next()) { if (__this->key_eq()(_ExtractKey()(__y_n->_M_v()), _ExtractKey()(*__itx))) break; if (!__y_n->_M_nxt || __other._M_bucket_index(__y_n->_M_next()) != __ybkt) return false; } typename __hashtable::const_iterator __ity(__y_n); for (auto __ity_end = __ity; __ity_end != __other.end(); ++__ity_end) if (--__x_count == 0) break; if (__x_count != 0) return false; if (!std::is_permutation(__itx, __itx_end, __ity)) return false; __itx = __itx_end; } return true; } /** * This type deals with all allocation and keeps an allocator instance * through inheritance to benefit from EBO when possible. */ template<typename _NodeAlloc> struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc> { private: using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>; public: using __node_type = typename _NodeAlloc::value_type; using __node_alloc_type = _NodeAlloc; // Use __gnu_cxx to benefit from _S_always_equal and al. using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>; using __value_alloc_traits = typename __node_alloc_traits::template rebind_traits<typename __node_type::value_type>; using __node_base = __detail::_Hash_node_base; using __bucket_type = __node_base*; using __bucket_alloc_type = __alloc_rebind<__node_alloc_type, __bucket_type>; using __bucket_alloc_traits = std::allocator_traits<__bucket_alloc_type>; _Hashtable_alloc() = default; _Hashtable_alloc(const _Hashtable_alloc&) = default; _Hashtable_alloc(_Hashtable_alloc&&) = default; template<typename _Alloc> _Hashtable_alloc(_Alloc&& __a) : __ebo_node_alloc(std::forward<_Alloc>(__a)) { } __node_alloc_type& _M_node_allocator() { return __ebo_node_alloc::_M_get(); } const __node_alloc_type& _M_node_allocator() const { return __ebo_node_alloc::_M_cget(); } // Allocate a node and construct an element within it. template<typename... _Args> __node_type* _M_allocate_node(_Args&&... __args); // Destroy the element within a node and deallocate the node. void _M_deallocate_node(__node_type* __n); // Deallocate a node. void _M_deallocate_node_ptr(__node_type* __n); // Deallocate the linked list of nodes pointed to by __n. // The elements within the nodes are destroyed. void _M_deallocate_nodes(__node_type* __n); __bucket_type* _M_allocate_buckets(std::size_t __bkt_count); void _M_deallocate_buckets(__bucket_type*, std::size_t __bkt_count); }; // Definitions of class template _Hashtable_alloc's out-of-line member // functions. template<typename _NodeAlloc> template<typename... _Args> auto _Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args) -> __node_type* { auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1); __node_type* __n = std::__to_address(__nptr); __try { ::new ((void*)__n) __node_type; __node_alloc_traits::construct(_M_node_allocator(), __n->_M_valptr(), std::forward<_Args>(__args)...); return __n; } __catch(...) { __node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1); __throw_exception_again; } } template<typename _NodeAlloc> void _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type* __n) { __node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr()); _M_deallocate_node_ptr(__n); } template<typename _NodeAlloc> void _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node_ptr(__node_type* __n) { typedef typename __node_alloc_traits::pointer _Ptr; auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n); __n->~__node_type(); __node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1); } template<typename _NodeAlloc> void _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n) { while (__n) { __node_type* __tmp = __n; __n = __n->_M_next(); _M_deallocate_node(__tmp); } } template<typename _NodeAlloc> typename _Hashtable_alloc<_NodeAlloc>::__bucket_type* _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __bkt_count) { __bucket_alloc_type __alloc(_M_node_allocator()); auto __ptr = __bucket_alloc_traits::allocate(__alloc, __bkt_count); __bucket_type* __p = std::__to_address(__ptr); __builtin_memset(__p, 0, __bkt_count * sizeof(__bucket_type)); return __p; } template<typename _NodeAlloc> void _Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts, std::size_t __bkt_count) { typedef typename __bucket_alloc_traits::pointer _Ptr; auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts); __bucket_alloc_type __alloc(_M_node_allocator()); __bucket_alloc_traits::deallocate(__alloc, __ptr, __bkt_count); } //@} hashtable-detail } // namespace __detail _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // _HASHTABLE_POLICY_H