| // Internal policy header for unordered_set and unordered_map -*- C++ -*- |
| |
| // Copyright (C) 2010, 2011, 2012 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 |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| namespace __detail |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| // Helper function: return distance(first, last) for forward |
| // iterators, or 0 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 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) |
| { |
| typedef typename std::iterator_traits<_Iterator>::iterator_category _Tag; |
| return __distance_fw(__first, __last, _Tag()); |
| } |
| |
| // Helper type used to detect when the hash functor is noexcept qualified or |
| // not |
| template <typename _Key, typename _Hash> |
| struct __is_noexcept_hash : std::integral_constant<bool, |
| noexcept(declval<const _Hash&>()(declval<const _Key&>()))> |
| {}; |
| |
| // Auxiliary types used for all instantiations of _Hashtable: nodes |
| // and iterators. |
| |
| // 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() |
| : _M_nxt() { } |
| _Hash_node_base(_Hash_node_base* __next) |
| : _M_nxt(__next) { } |
| }; |
| |
| template<typename _Value, bool __cache_hash_code> |
| struct _Hash_node; |
| |
| template<typename _Value> |
| struct _Hash_node<_Value, true> : _Hash_node_base |
| { |
| _Value _M_v; |
| std::size_t _M_hash_code; |
| |
| template<typename... _Args> |
| _Hash_node(_Args&&... __args) |
| : _M_v(std::forward<_Args>(__args)...), _M_hash_code() { } |
| |
| _Hash_node* _M_next() const |
| { return static_cast<_Hash_node*>(_M_nxt); } |
| }; |
| |
| template<typename _Value> |
| struct _Hash_node<_Value, false> : _Hash_node_base |
| { |
| _Value _M_v; |
| |
| template<typename... _Args> |
| _Hash_node(_Args&&... __args) |
| : _M_v(std::forward<_Args>(__args)...) { } |
| |
| _Hash_node* _M_next() const |
| { return static_cast<_Hash_node*>(_M_nxt); } |
| }; |
| |
| // Node iterators, used to iterate through all the hashtable. |
| template<typename _Value, bool __cache> |
| struct _Node_iterator_base |
| { |
| _Node_iterator_base(_Hash_node<_Value, __cache>* __p) |
| : _M_cur(__p) { } |
| |
| void |
| _M_incr() |
| { _M_cur = _M_cur->_M_next(); } |
| |
| _Hash_node<_Value, __cache>* _M_cur; |
| }; |
| |
| template<typename _Value, bool __cache> |
| inline bool |
| operator==(const _Node_iterator_base<_Value, __cache>& __x, |
| const _Node_iterator_base<_Value, __cache>& __y) |
| { return __x._M_cur == __y._M_cur; } |
| |
| template<typename _Value, bool __cache> |
| inline bool |
| operator!=(const _Node_iterator_base<_Value, __cache>& __x, |
| const _Node_iterator_base<_Value, __cache>& __y) |
| { return __x._M_cur != __y._M_cur; } |
| |
| template<typename _Value, bool __constant_iterators, bool __cache> |
| struct _Node_iterator |
| : public _Node_iterator_base<_Value, __cache> |
| { |
| 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; |
| |
| _Node_iterator() |
| : _Node_iterator_base<_Value, __cache>(0) { } |
| |
| explicit |
| _Node_iterator(_Hash_node<_Value, __cache>* __p) |
| : _Node_iterator_base<_Value, __cache>(__p) { } |
| |
| reference |
| operator*() const |
| { return this->_M_cur->_M_v; } |
| |
| pointer |
| operator->() const |
| { return std::__addressof(this->_M_cur->_M_v); } |
| |
| _Node_iterator& |
| operator++() |
| { |
| this->_M_incr(); |
| return *this; |
| } |
| |
| _Node_iterator |
| operator++(int) |
| { |
| _Node_iterator __tmp(*this); |
| this->_M_incr(); |
| return __tmp; |
| } |
| }; |
| |
| template<typename _Value, bool __constant_iterators, bool __cache> |
| struct _Node_const_iterator |
| : public _Node_iterator_base<_Value, __cache> |
| { |
| 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; |
| |
| _Node_const_iterator() |
| : _Node_iterator_base<_Value, __cache>(0) { } |
| |
| explicit |
| _Node_const_iterator(_Hash_node<_Value, __cache>* __p) |
| : _Node_iterator_base<_Value, __cache>(__p) { } |
| |
| _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators, |
| __cache>& __x) |
| : _Node_iterator_base<_Value, __cache>(__x._M_cur) { } |
| |
| reference |
| operator*() const |
| { return this->_M_cur->_M_v; } |
| |
| pointer |
| operator->() const |
| { return std::__addressof(this->_M_cur->_M_v); } |
| |
| _Node_const_iterator& |
| operator++() |
| { |
| this->_M_incr(); |
| return *this; |
| } |
| |
| _Node_const_iterator |
| operator++(int) |
| { |
| _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 |
| { 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 |
| { |
| _Prime_rehash_policy(float __z = 1.0) |
| : _M_max_load_factor(__z), _M_prev_resize(0), _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; |
| |
| // __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::pair<std::size_t, std::size_t> _State; |
| |
| _State |
| _M_state() const |
| { return std::make_pair(_M_prev_resize, _M_next_resize); } |
| |
| void |
| _M_reset(const _State& __state) |
| { |
| _M_prev_resize = __state.first; |
| _M_next_resize = __state.second; |
| } |
| |
| enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 }; |
| |
| static const std::size_t _S_growth_factor = 2; |
| |
| float _M_max_load_factor; |
| mutable std::size_t _M_prev_resize; |
| mutable std::size_t _M_next_resize; |
| }; |
| |
| extern const unsigned long __prime_list[]; |
| |
| // XXX This is a hack. There's no good reason for any of |
| // _Prime_rehash_policy's member functions to be inline. |
| |
| // Return a prime no smaller than n. |
| inline std::size_t |
| _Prime_rehash_policy:: |
| _M_next_bkt(std::size_t __n) const |
| { |
| // Optimize lookups involving the first elements of __prime_list. |
| // (useful to speed-up, eg, constructors) |
| static const unsigned char __fast_bkt[12] |
| = { 2, 2, 2, 3, 5, 5, 7, 7, 11, 11, 11, 11 }; |
| |
| const std::size_t __grown_n = __n * _S_growth_factor; |
| if (__grown_n <= 11) |
| { |
| _M_prev_resize = 0; |
| _M_next_resize |
| = __builtin_ceil(__fast_bkt[__grown_n] |
| * (long double)_M_max_load_factor); |
| return __fast_bkt[__grown_n]; |
| } |
| |
| const unsigned long* __next_bkt |
| = std::lower_bound(__prime_list + 5, __prime_list + _S_n_primes, |
| __grown_n); |
| const unsigned long* __prev_bkt |
| = std::lower_bound(__prime_list + 1, __next_bkt, __n / _S_growth_factor); |
| |
| _M_prev_resize |
| = __builtin_floor(*(__prev_bkt - 1) * (long double)_M_max_load_factor); |
| _M_next_resize |
| = __builtin_ceil(*__next_bkt * (long double)_M_max_load_factor); |
| return *__next_bkt; |
| } |
| |
| // Return the smallest prime p such that alpha p >= n, where alpha |
| // is the load factor. |
| inline std::size_t |
| _Prime_rehash_policy:: |
| _M_bkt_for_elements(std::size_t __n) const |
| { return _M_next_bkt(__builtin_ceil(__n / (long double)_M_max_load_factor)); } |
| |
| // Finds the smallest prime p such that alpha p > __n_elt + __n_ins. |
| // If p > __n_bkt, return make_pair(true, p); otherwise return |
| // make_pair(false, 0). In principle this isn't very different from |
| // _M_bkt_for_elements. |
| |
| // The only tricky part is that we're caching the element count at |
| // which we need to rehash, so we don't have to do a floating-point |
| // multiply for every insertion. |
| |
| inline std::pair<bool, std::size_t> |
| _Prime_rehash_policy:: |
| _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, |
| std::size_t __n_ins) const |
| { |
| if (__n_elt + __n_ins >= _M_next_resize) |
| { |
| long double __min_bkts = (__n_elt + __n_ins) |
| / (long double)_M_max_load_factor; |
| if (__min_bkts >= __n_bkt) |
| return std::make_pair(true, |
| _M_next_bkt(__builtin_floor(__min_bkts) + 1)); |
| else |
| { |
| _M_next_resize |
| = __builtin_floor(__n_bkt * (long double)_M_max_load_factor); |
| return std::make_pair(false, 0); |
| } |
| } |
| else if (__n_elt + __n_ins < _M_prev_resize) |
| { |
| long double __min_bkts = (__n_elt + __n_ins) |
| / (long double)_M_max_load_factor; |
| return std::make_pair(true, |
| _M_next_bkt(__builtin_floor(__min_bkts) + 1)); |
| } |
| else |
| return std::make_pair(false, 0); |
| } |
| |
| // 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 the "curiously recurring template |
| // pattern" for them. |
| |
| // class template _Map_base. If the hashtable has a value type of |
| // the form pair<T1, T2> and a key extraction policy 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 _Ex, bool __unique, |
| typename _Hashtable> |
| struct _Map_base { }; |
| |
| template<typename _Key, typename _Pair, typename _Hashtable> |
| struct _Map_base<_Key, _Pair, std::_Select1st<_Pair>, false, _Hashtable> |
| { |
| typedef typename _Pair::second_type mapped_type; |
| }; |
| |
| template<typename _Key, typename _Pair, typename _Hashtable> |
| struct _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable> |
| { |
| typedef typename _Pair::second_type mapped_type; |
| |
| mapped_type& |
| operator[](const _Key& __k); |
| |
| mapped_type& |
| operator[](_Key&& __k); |
| |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // DR 761. unordered_map needs an at() member function. |
| mapped_type& |
| at(const _Key& __k); |
| |
| const mapped_type& |
| at(const _Key& __k) const; |
| }; |
| |
| template<typename _Key, typename _Pair, typename _Hashtable> |
| typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>, |
| true, _Hashtable>::mapped_type& |
| _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>:: |
| operator[](const _Key& __k) |
| { |
| _Hashtable* __h = static_cast<_Hashtable*>(this); |
| typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k); |
| std::size_t __n = __h->_M_bucket_index(__k, __code); |
| |
| typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code); |
| if (!__p) |
| return __h->_M_insert_bucket(std::make_pair(__k, mapped_type()), |
| __n, __code)->second; |
| return (__p->_M_v).second; |
| } |
| |
| template<typename _Key, typename _Pair, typename _Hashtable> |
| typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>, |
| true, _Hashtable>::mapped_type& |
| _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>:: |
| operator[](_Key&& __k) |
| { |
| _Hashtable* __h = static_cast<_Hashtable*>(this); |
| typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k); |
| std::size_t __n = __h->_M_bucket_index(__k, __code); |
| |
| typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code); |
| if (!__p) |
| return __h->_M_insert_bucket(std::make_pair(std::move(__k), |
| mapped_type()), |
| __n, __code)->second; |
| return (__p->_M_v).second; |
| } |
| |
| template<typename _Key, typename _Pair, typename _Hashtable> |
| typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>, |
| true, _Hashtable>::mapped_type& |
| _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>:: |
| at(const _Key& __k) |
| { |
| _Hashtable* __h = static_cast<_Hashtable*>(this); |
| typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k); |
| std::size_t __n = __h->_M_bucket_index(__k, __code); |
| |
| typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code); |
| if (!__p) |
| __throw_out_of_range(__N("_Map_base::at")); |
| return (__p->_M_v).second; |
| } |
| |
| template<typename _Key, typename _Pair, typename _Hashtable> |
| const typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>, |
| true, _Hashtable>::mapped_type& |
| _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>:: |
| at(const _Key& __k) const |
| { |
| const _Hashtable* __h = static_cast<const _Hashtable*>(this); |
| typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k); |
| std::size_t __n = __h->_M_bucket_index(__k, __code); |
| |
| typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code); |
| if (!__p) |
| __throw_out_of_range(__N("_Map_base::at")); |
| return (__p->_M_v).second; |
| } |
| |
| // class template _Rehash_base. Give hashtable the max_load_factor |
| // functions and reserve iff the rehash policy is _Prime_rehash_policy. |
| template<typename _RehashPolicy, typename _Hashtable> |
| struct _Rehash_base { }; |
| |
| template<typename _Hashtable> |
| struct _Rehash_base<_Prime_rehash_policy, _Hashtable> |
| { |
| 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(_Prime_rehash_policy(__z)); |
| } |
| |
| void |
| reserve(std::size_t __n) |
| { |
| _Hashtable* __this = static_cast<_Hashtable*>(this); |
| __this->rehash(__builtin_ceil(__n / max_load_factor())); |
| } |
| }; |
| |
| // Helper class using EBO when it is not forbidden, type is not final, |
| // and when it worth it, 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> |
| // See PR53067. |
| : public _Tp |
| { |
| _Hashtable_ebo_helper() = default; |
| _Hashtable_ebo_helper(const _Tp& __tp) : _Tp(__tp) |
| { } |
| |
| static const _Tp& |
| _S_cget(const _Hashtable_ebo_helper& __eboh) |
| { return static_cast<const _Tp&>(__eboh); } |
| |
| static _Tp& |
| _S_get(_Hashtable_ebo_helper& __eboh) |
| { return static_cast<_Tp&>(__eboh); } |
| }; |
| |
| // Specialization not using EBO. |
| template<int _Nm, typename _Tp> |
| struct _Hashtable_ebo_helper<_Nm, _Tp, false> |
| { |
| _Hashtable_ebo_helper() = default; |
| _Hashtable_ebo_helper(const _Tp& __tp) : _M_tp(__tp) |
| { } |
| |
| static const _Tp& |
| _S_cget(const _Hashtable_ebo_helper& __eboh) |
| { return __eboh._M_tp; } |
| |
| static _Tp& |
| _S_get(_Hashtable_ebo_helper& __eboh) |
| { return __eboh._M_tp; } |
| |
| private: |
| _Tp _M_tp; |
| }; |
| |
| // 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: 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> |
| // See PR53067. |
| : public _Hashtable_ebo_helper<0, _ExtractKey>, |
| public _Hashtable_ebo_helper<1, _Hash> |
| { |
| private: |
| typedef _Hashtable_ebo_helper<0, _ExtractKey> _EboExtractKey; |
| typedef _Hashtable_ebo_helper<1, _Hash> _EboHash; |
| |
| protected: |
| // We need the default constructor for the local iterators. |
| _Hash_code_base() = default; |
| _Hash_code_base(const _ExtractKey& __ex, |
| const _H1&, const _H2&, const _Hash& __h) |
| : _EboExtractKey(__ex), _EboHash(__h) { } |
| |
| typedef void* _Hash_code_type; |
| |
| _Hash_code_type |
| _M_hash_code(const _Key& __key) const |
| { return 0; } |
| |
| std::size_t |
| _M_bucket_index(const _Key& __k, _Hash_code_type, |
| std::size_t __n) const |
| { return _M_ranged_hash()(__k, __n); } |
| |
| std::size_t |
| _M_bucket_index(const _Hash_node<_Value, false>* __p, |
| std::size_t __n) const |
| { return _M_ranged_hash()(_M_extract()(__p->_M_v), __n); } |
| |
| void |
| _M_store_code(_Hash_node<_Value, false>*, _Hash_code_type) const |
| { } |
| |
| void |
| _M_copy_code(_Hash_node<_Value, false>*, |
| const _Hash_node<_Value, false>*) const |
| { } |
| |
| void |
| _M_swap(_Hash_code_base& __x) |
| { |
| std::swap(_M_extract(), __x._M_extract()); |
| std::swap(_M_ranged_hash(), __x._M_ranged_hash()); |
| } |
| |
| protected: |
| const _ExtractKey& |
| _M_extract() const { return _EboExtractKey::_S_cget(*this); } |
| _ExtractKey& |
| _M_extract() { return _EboExtractKey::_S_get(*this); } |
| const _Hash& |
| _M_ranged_hash() const { return _EboHash::_S_cget(*this); } |
| _Hash& |
| _M_ranged_hash() { return _EboHash::_S_get(*this); } |
| }; |
| |
| // 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 TR1. |
| template<typename _Key, typename _Value, typename _ExtractKey, |
| typename _H1, typename _H2> |
| struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, |
| _Default_ranged_hash, false> |
| // See PR53067. |
| : public _Hashtable_ebo_helper<0, _ExtractKey>, |
| public _Hashtable_ebo_helper<1, _H1>, |
| public _Hashtable_ebo_helper<2, _H2> |
| { |
| private: |
| typedef _Hashtable_ebo_helper<0, _ExtractKey> _EboExtractKey; |
| typedef _Hashtable_ebo_helper<1, _H1> _EboH1; |
| typedef _Hashtable_ebo_helper<2, _H2> _EboH2; |
| |
| public: |
| typedef _H1 hasher; |
| |
| hasher |
| hash_function() const |
| { return _M_h1(); } |
| |
| protected: |
| // We need the default constructor for the local iterators. |
| _Hash_code_base() = default; |
| _Hash_code_base(const _ExtractKey& __ex, |
| const _H1& __h1, const _H2& __h2, |
| const _Default_ranged_hash&) |
| : _EboExtractKey(__ex), _EboH1(__h1), _EboH2(__h2) { } |
| |
| typedef std::size_t _Hash_code_type; |
| |
| _Hash_code_type |
| _M_hash_code(const _Key& __k) const |
| { return _M_h1()(__k); } |
| |
| std::size_t |
| _M_bucket_index(const _Key&, _Hash_code_type __c, |
| std::size_t __n) const |
| { return _M_h2()(__c, __n); } |
| |
| std::size_t |
| _M_bucket_index(const _Hash_node<_Value, false>* __p, |
| std::size_t __n) const |
| { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v)), __n); } |
| |
| void |
| _M_store_code(_Hash_node<_Value, false>*, _Hash_code_type) const |
| { } |
| |
| void |
| _M_copy_code(_Hash_node<_Value, false>*, |
| const _Hash_node<_Value, false>*) const |
| { } |
| |
| void |
| _M_swap(_Hash_code_base& __x) |
| { |
| std::swap(_M_extract(), __x._M_extract()); |
| std::swap(_M_h1(), __x._M_h1()); |
| std::swap(_M_h2(), __x._M_h2()); |
| } |
| |
| protected: |
| const _ExtractKey& |
| _M_extract() const { return _EboExtractKey::_S_cget(*this); } |
| _ExtractKey& |
| _M_extract() { return _EboExtractKey::_S_get(*this); } |
| const _H1& |
| _M_h1() const { return _EboH1::_S_cget(*this); } |
| _H1& |
| _M_h1() { return _EboH1::_S_get(*this); } |
| const _H2& |
| _M_h2() const { return _EboH2::_S_cget(*this); } |
| _H2& |
| _M_h2() { return _EboH2::_S_get(*this); } |
| }; |
| |
| // Specialization: hash function and range-hashing function, |
| // caching hash codes. H is provided but ignored. Provides |
| // typedef and accessor required by TR1. |
| template<typename _Key, typename _Value, typename _ExtractKey, |
| typename _H1, typename _H2> |
| struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, |
| _Default_ranged_hash, true> |
| // See PR53067. |
| : public _Hashtable_ebo_helper<0, _ExtractKey>, |
| public _Hashtable_ebo_helper<1, _H1>, |
| public _Hashtable_ebo_helper<2, _H2> |
| { |
| private: |
| typedef _Hashtable_ebo_helper<0, _ExtractKey> _EboExtractKey; |
| typedef _Hashtable_ebo_helper<1, _H1> _EboH1; |
| typedef _Hashtable_ebo_helper<2, _H2> _EboH2; |
| |
| public: |
| typedef _H1 hasher; |
| |
| hasher |
| hash_function() const |
| { return _M_h1(); } |
| |
| protected: |
| _Hash_code_base(const _ExtractKey& __ex, |
| const _H1& __h1, const _H2& __h2, |
| const _Default_ranged_hash&) |
| : _EboExtractKey(__ex), _EboH1(__h1), _EboH2(__h2) { } |
| |
| typedef std::size_t _Hash_code_type; |
| |
| _Hash_code_type |
| _M_hash_code(const _Key& __k) const |
| { return _M_h1()(__k); } |
| |
| std::size_t |
| _M_bucket_index(const _Key&, _Hash_code_type __c, |
| std::size_t __n) const |
| { return _M_h2()(__c, __n); } |
| |
| std::size_t |
| _M_bucket_index(const _Hash_node<_Value, true>* __p, |
| std::size_t __n) const |
| { return _M_h2()(__p->_M_hash_code, __n); } |
| |
| void |
| _M_store_code(_Hash_node<_Value, true>* __n, _Hash_code_type __c) const |
| { __n->_M_hash_code = __c; } |
| |
| void |
| _M_copy_code(_Hash_node<_Value, true>* __to, |
| const _Hash_node<_Value, true>* __from) const |
| { __to->_M_hash_code = __from->_M_hash_code; } |
| |
| void |
| _M_swap(_Hash_code_base& __x) |
| { |
| std::swap(_M_extract(), __x._M_extract()); |
| std::swap(_M_h1(), __x._M_h1()); |
| std::swap(_M_h2(), __x._M_h2()); |
| } |
| |
| protected: |
| const _ExtractKey& |
| _M_extract() const { return _EboExtractKey::_S_cget(*this); } |
| _ExtractKey& |
| _M_extract() { return _EboExtractKey::_S_get(*this); } |
| const _H1& |
| _M_h1() const { return _EboH1::_S_cget(*this); } |
| _H1& |
| _M_h1() { return _EboH1::_S_get(*this); } |
| const _H2& |
| _M_h2() const { return _EboH2::_S_cget(*this); } |
| _H2& |
| _M_h2() { return _EboH2::_S_get(*this); } |
| }; |
| |
| template <typename _Key, typename _Value, typename _ExtractKey, |
| typename _Equal, typename _HashCodeType, |
| bool __cache_hash_code> |
| struct _Equal_helper; |
| |
| template<typename _Key, typename _Value, typename _ExtractKey, |
| typename _Equal, typename _HashCodeType> |
| struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, true> |
| { |
| static bool |
| _S_equals(const _Equal& __eq, const _ExtractKey& __extract, |
| const _Key& __k, _HashCodeType __c, |
| _Hash_node<_Value, true>* __n) |
| { return __c == __n->_M_hash_code |
| && __eq(__k, __extract(__n->_M_v)); } |
| }; |
| |
| template<typename _Key, typename _Value, typename _ExtractKey, |
| typename _Equal, typename _HashCodeType> |
| struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, false> |
| { |
| static bool |
| _S_equals(const _Equal& __eq, const _ExtractKey& __extract, |
| const _Key& __k, _HashCodeType, |
| _Hash_node<_Value, false>* __n) |
| { return __eq(__k, __extract(__n->_M_v)); } |
| }; |
| |
| // Helper class adding management of _Equal functor to _Hash_code_base |
| // type. |
| template<typename _Key, typename _Value, |
| typename _ExtractKey, typename _Equal, |
| typename _H1, typename _H2, typename _Hash, |
| bool __cache_hash_code> |
| struct _Hashtable_base |
| // See PR53067. |
| : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, |
| __cache_hash_code>, |
| public _Hashtable_ebo_helper<0, _Equal> |
| { |
| private: |
| typedef _Hashtable_ebo_helper<0, _Equal> _EboEqual; |
| |
| protected: |
| typedef _Hash_code_base<_Key, _Value, _ExtractKey, |
| _H1, _H2, _Hash, __cache_hash_code> _HCBase; |
| typedef typename _HCBase::_Hash_code_type _Hash_code_type; |
| |
| _Hashtable_base(const _ExtractKey& __ex, |
| const _H1& __h1, const _H2& __h2, |
| const _Hash& __hash, const _Equal& __eq) |
| : _HCBase(__ex, __h1, __h2, __hash), _EboEqual(__eq) { } |
| |
| bool |
| _M_equals(const _Key& __k, _Hash_code_type __c, |
| _Hash_node<_Value, __cache_hash_code>* __n) const |
| { |
| typedef _Equal_helper<_Key, _Value, _ExtractKey, |
| _Equal, _Hash_code_type, |
| __cache_hash_code> _EqualHelper; |
| return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(), |
| __k, __c, __n); |
| } |
| |
| void |
| _M_swap(_Hashtable_base& __x) |
| { |
| _HCBase::_M_swap(__x); |
| std::swap(_M_eq(), __x._M_eq()); |
| } |
| |
| protected: |
| const _Equal& |
| _M_eq() const { return _EboEqual::_S_cget(*this); } |
| _Equal& |
| _M_eq() { return _EboEqual::_S_get(*this); } |
| }; |
| |
| // 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; |
| |
| template<typename _Key, typename _Value, typename _ExtractKey, |
| typename _H1, typename _H2, typename _Hash> |
| struct _Local_iterator_base<_Key, _Value, _ExtractKey, |
| _H1, _H2, _Hash, true> |
| // See PR53067. |
| : public _H2 |
| { |
| _Local_iterator_base() = default; |
| _Local_iterator_base(_Hash_node<_Value, true>* __p, |
| std::size_t __bkt, std::size_t __bkt_count) |
| : _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 = _M_h2()(_M_cur->_M_hash_code, _M_bucket_count); |
| if (__bkt != _M_bucket) |
| _M_cur = nullptr; |
| } |
| } |
| |
| const _H2& _M_h2() const |
| { return *this; } |
| |
| _Hash_node<_Value, true>* _M_cur; |
| std::size_t _M_bucket; |
| std::size_t _M_bucket_count; |
| }; |
| |
| template<typename _Key, typename _Value, typename _ExtractKey, |
| typename _H1, typename _H2, typename _Hash> |
| struct _Local_iterator_base<_Key, _Value, _ExtractKey, |
| _H1, _H2, _Hash, false> |
| // See PR53067. |
| : public _Hash_code_base<_Key, _Value, _ExtractKey, |
| _H1, _H2, _Hash, false> |
| { |
| _Local_iterator_base() = default; |
| _Local_iterator_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) { } |
| |
| void |
| _M_incr() |
| { |
| _M_cur = _M_cur->_M_next(); |
| if (_M_cur) |
| { |
| std::size_t __bkt = this->_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; |
| }; |
| |
| 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_cur == __y._M_cur; } |
| |
| 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_cur != __y._M_cur; } |
| |
| 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> |
| { |
| 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; |
| |
| explicit |
| _Local_iterator(_Hash_node<_Value, __cache>* __p, |
| std::size_t __bkt, std::size_t __bkt_count) |
| : _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, |
| __cache>(__p, __bkt, __bkt_count) |
| { } |
| |
| reference |
| operator*() const |
| { return this->_M_cur->_M_v; } |
| |
| pointer |
| operator->() const |
| { return std::__addressof(this->_M_cur->_M_v); } |
| |
| _Local_iterator& |
| operator++() |
| { |
| this->_M_incr(); |
| return *this; |
| } |
| |
| _Local_iterator |
| operator++(int) |
| { |
| _Local_iterator __tmp(*this); |
| this->_M_incr(); |
| return __tmp; |
| } |
| }; |
| |
| 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> |
| { |
| 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; |
| |
| explicit |
| _Local_const_iterator(_Hash_node<_Value, __cache>* __p, |
| std::size_t __bkt, std::size_t __bkt_count) |
| : _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, |
| __cache>(__p, __bkt, __bkt_count) |
| { } |
| |
| _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey, |
| _H1, _H2, _Hash, |
| __constant_iterators, |
| __cache>& __x) |
| : _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, |
| __cache>(__x._M_cur, __x._M_bucket, |
| __x._M_bucket_count) |
| { } |
| |
| reference |
| operator*() const |
| { return this->_M_cur->_M_v; } |
| |
| pointer |
| operator->() const |
| { return std::__addressof(this->_M_cur->_M_v); } |
| |
| _Local_const_iterator& |
| operator++() |
| { |
| this->_M_incr(); |
| return *this; |
| } |
| |
| _Local_const_iterator |
| operator++(int) |
| { |
| _Local_const_iterator __tmp(*this); |
| this->_M_incr(); |
| return __tmp; |
| } |
| }; |
| |
| |
| // Class template _Equality_base. 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 _ExtractKey, bool __unique_keys, |
| typename _Hashtable> |
| struct _Equality_base; |
| |
| template<typename _ExtractKey, typename _Hashtable> |
| struct _Equality_base<_ExtractKey, true, _Hashtable> |
| { |
| bool _M_equal(const _Hashtable&) const; |
| }; |
| |
| template<typename _ExtractKey, typename _Hashtable> |
| bool |
| _Equality_base<_ExtractKey, true, _Hashtable>:: |
| _M_equal(const _Hashtable& __other) const |
| { |
| const _Hashtable* __this = static_cast<const _Hashtable*>(this); |
| |
| if (__this->size() != __other.size()) |
| return false; |
| |
| for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx) |
| { |
| const auto __ity = __other.find(_ExtractKey()(*__itx)); |
| if (__ity == __other.end() || !bool(*__ity == *__itx)) |
| return false; |
| } |
| return true; |
| } |
| |
| template<typename _ExtractKey, typename _Hashtable> |
| struct _Equality_base<_ExtractKey, false, _Hashtable> |
| { |
| bool _M_equal(const _Hashtable&) const; |
| |
| private: |
| template<typename _Uiterator> |
| static bool |
| _S_is_permutation(_Uiterator, _Uiterator, _Uiterator); |
| }; |
| |
| // See std::is_permutation in N3068. |
| template<typename _ExtractKey, typename _Hashtable> |
| template<typename _Uiterator> |
| bool |
| _Equality_base<_ExtractKey, false, _Hashtable>:: |
| _S_is_permutation(_Uiterator __first1, _Uiterator __last1, |
| _Uiterator __first2) |
| { |
| for (; __first1 != __last1; ++__first1, ++__first2) |
| if (!(*__first1 == *__first2)) |
| break; |
| |
| if (__first1 == __last1) |
| return true; |
| |
| _Uiterator __last2 = __first2; |
| std::advance(__last2, std::distance(__first1, __last1)); |
| |
| for (_Uiterator __it1 = __first1; __it1 != __last1; ++__it1) |
| { |
| _Uiterator __tmp = __first1; |
| while (__tmp != __it1 && !bool(*__tmp == *__it1)) |
| ++__tmp; |
| |
| // We've seen this one before. |
| if (__tmp != __it1) |
| continue; |
| |
| std::ptrdiff_t __n2 = 0; |
| for (__tmp = __first2; __tmp != __last2; ++__tmp) |
| if (*__tmp == *__it1) |
| ++__n2; |
| |
| if (!__n2) |
| return false; |
| |
| std::ptrdiff_t __n1 = 0; |
| for (__tmp = __it1; __tmp != __last1; ++__tmp) |
| if (*__tmp == *__it1) |
| ++__n1; |
| |
| if (__n1 != __n2) |
| return false; |
| } |
| return true; |
| } |
| |
| template<typename _ExtractKey, typename _Hashtable> |
| bool |
| _Equality_base<_ExtractKey, false, _Hashtable>:: |
| _M_equal(const _Hashtable& __other) const |
| { |
| const _Hashtable* __this = static_cast<const _Hashtable*>(this); |
| |
| if (__this->size() != __other.size()) |
| return false; |
| |
| for (auto __itx = __this->begin(); __itx != __this->end();) |
| { |
| const auto __xrange = __this->equal_range(_ExtractKey()(*__itx)); |
| const auto __yrange = __other.equal_range(_ExtractKey()(*__itx)); |
| |
| if (std::distance(__xrange.first, __xrange.second) |
| != std::distance(__yrange.first, __yrange.second)) |
| return false; |
| |
| if (!_S_is_permutation(__xrange.first, |
| __xrange.second, |
| __yrange.first)) |
| return false; |
| |
| __itx = __xrange.second; |
| } |
| return true; |
| } |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace __detail |
| } // namespace std |
| |
| #endif // _HASHTABLE_POLICY_H |
