| // Internal policy header for unordered_set and unordered_map -*- C++ -*- |
| |
| // Copyright (C) 2010, 2011 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()); |
| } |
| |
| // 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. |
| template<typename _Value, bool __cache_hash_code> |
| struct _Hash_node; |
| |
| template<typename _Value> |
| struct _Hash_node<_Value, true> |
| { |
| _Value _M_v; |
| std::size_t _M_hash_code; |
| _Hash_node* _M_next; |
| |
| template<typename... _Args> |
| _Hash_node(_Args&&... __args) |
| : _M_v(std::forward<_Args>(__args)...), |
| _M_hash_code(), _M_next() { } |
| }; |
| |
| template<typename _Value> |
| struct _Hash_node<_Value, false> |
| { |
| _Value _M_v; |
| _Hash_node* _M_next; |
| |
| template<typename... _Args> |
| _Hash_node(_Args&&... __args) |
| : _M_v(std::forward<_Args>(__args)...), |
| _M_next() { } |
| }; |
| |
| // Local iterators, used to iterate within a bucket but not between |
| // buckets. |
| 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; |
| } |
| }; |
| |
| template<typename _Value, bool __cache> |
| struct _Hashtable_iterator_base |
| { |
| _Hashtable_iterator_base(_Hash_node<_Value, __cache>* __node, |
| _Hash_node<_Value, __cache>** __bucket) |
| : _M_cur_node(__node), _M_cur_bucket(__bucket) { } |
| |
| void |
| _M_incr() |
| { |
| _M_cur_node = _M_cur_node->_M_next; |
| if (!_M_cur_node) |
| _M_incr_bucket(); |
| } |
| |
| void |
| _M_incr_bucket(); |
| |
| _Hash_node<_Value, __cache>* _M_cur_node; |
| _Hash_node<_Value, __cache>** _M_cur_bucket; |
| }; |
| |
| // Global iterators, used for arbitrary iteration within a hash |
| // table. Larger and more expensive than local iterators. |
| template<typename _Value, bool __cache> |
| void |
| _Hashtable_iterator_base<_Value, __cache>:: |
| _M_incr_bucket() |
| { |
| ++_M_cur_bucket; |
| |
| // This loop requires the bucket array to have a non-null sentinel. |
| while (!*_M_cur_bucket) |
| ++_M_cur_bucket; |
| _M_cur_node = *_M_cur_bucket; |
| } |
| |
| template<typename _Value, bool __cache> |
| inline bool |
| operator==(const _Hashtable_iterator_base<_Value, __cache>& __x, |
| const _Hashtable_iterator_base<_Value, __cache>& __y) |
| { return __x._M_cur_node == __y._M_cur_node; } |
| |
| template<typename _Value, bool __cache> |
| inline bool |
| operator!=(const _Hashtable_iterator_base<_Value, __cache>& __x, |
| const _Hashtable_iterator_base<_Value, __cache>& __y) |
| { return __x._M_cur_node != __y._M_cur_node; } |
| |
| template<typename _Value, bool __constant_iterators, bool __cache> |
| struct _Hashtable_iterator |
| : public _Hashtable_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; |
| |
| _Hashtable_iterator() |
| : _Hashtable_iterator_base<_Value, __cache>(0, 0) { } |
| |
| _Hashtable_iterator(_Hash_node<_Value, __cache>* __p, |
| _Hash_node<_Value, __cache>** __b) |
| : _Hashtable_iterator_base<_Value, __cache>(__p, __b) { } |
| |
| explicit |
| _Hashtable_iterator(_Hash_node<_Value, __cache>** __b) |
| : _Hashtable_iterator_base<_Value, __cache>(*__b, __b) { } |
| |
| reference |
| operator*() const |
| { return this->_M_cur_node->_M_v; } |
| |
| pointer |
| operator->() const |
| { return std::__addressof(this->_M_cur_node->_M_v); } |
| |
| _Hashtable_iterator& |
| operator++() |
| { |
| this->_M_incr(); |
| return *this; |
| } |
| |
| _Hashtable_iterator |
| operator++(int) |
| { |
| _Hashtable_iterator __tmp(*this); |
| this->_M_incr(); |
| return __tmp; |
| } |
| }; |
| |
| template<typename _Value, bool __constant_iterators, bool __cache> |
| struct _Hashtable_const_iterator |
| : public _Hashtable_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; |
| |
| _Hashtable_const_iterator() |
| : _Hashtable_iterator_base<_Value, __cache>(0, 0) { } |
| |
| _Hashtable_const_iterator(_Hash_node<_Value, __cache>* __p, |
| _Hash_node<_Value, __cache>** __b) |
| : _Hashtable_iterator_base<_Value, __cache>(__p, __b) { } |
| |
| explicit |
| _Hashtable_const_iterator(_Hash_node<_Value, __cache>** __b) |
| : _Hashtable_iterator_base<_Value, __cache>(*__b, __b) { } |
| |
| _Hashtable_const_iterator(const _Hashtable_iterator<_Value, |
| __constant_iterators, __cache>& __x) |
| : _Hashtable_iterator_base<_Value, __cache>(__x._M_cur_node, |
| __x._M_cur_bucket) { } |
| |
| reference |
| operator*() const |
| { return this->_M_cur_node->_M_v; } |
| |
| pointer |
| operator->() const |
| { return std::__addressof(this->_M_cur_node->_M_v); } |
| |
| _Hashtable_const_iterator& |
| operator++() |
| { |
| this->_M_incr(); |
| return *this; |
| } |
| |
| _Hashtable_const_iterator |
| operator++(int) |
| { |
| _Hashtable_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_growth_factor(2.f), _M_next_resize(0) { } |
| |
| float |
| max_load_factor() const |
| { 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; |
| |
| enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 }; |
| |
| float _M_max_load_factor; |
| float _M_growth_factor; |
| 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 |
| { |
| const unsigned long* __p = std::lower_bound(__prime_list, __prime_list |
| + _S_n_primes, __n); |
| _M_next_resize = |
| static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor)); |
| return *__p; |
| } |
| |
| // 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 |
| { |
| const float __min_bkts = __n / _M_max_load_factor; |
| const unsigned long* __p = std::lower_bound(__prime_list, __prime_list |
| + _S_n_primes, __min_bkts); |
| _M_next_resize = |
| static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor)); |
| return *__p; |
| } |
| |
| // 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) |
| { |
| float __min_bkts = ((float(__n_ins) + float(__n_elt)) |
| / _M_max_load_factor); |
| if (__min_bkts > __n_bkt) |
| { |
| __min_bkts = std::max(__min_bkts, _M_growth_factor * __n_bkt); |
| const unsigned long* __p = |
| std::lower_bound(__prime_list, __prime_list + _S_n_primes, |
| __min_bkts); |
| _M_next_resize = static_cast<std::size_t> |
| (__builtin_ceil(*__p * _M_max_load_factor)); |
| return std::make_pair(true, *__p); |
| } |
| else |
| { |
| _M_next_resize = static_cast<std::size_t> |
| (__builtin_ceil(__n_bkt * _M_max_load_factor)); |
| return std::make_pair(false, 0); |
| } |
| } |
| 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, |
| __h->_M_bucket_count); |
| |
| typename _Hashtable::_Node* __p = |
| __h->_M_find_node(__h->_M_buckets[__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, |
| __h->_M_bucket_count); |
| |
| typename _Hashtable::_Node* __p = |
| __h->_M_find_node(__h->_M_buckets[__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, |
| __h->_M_bucket_count); |
| |
| typename _Hashtable::_Node* __p = |
| __h->_M_find_node(__h->_M_buckets[__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, |
| __h->_M_bucket_count); |
| |
| typename _Hashtable::_Node* __p = |
| __h->_M_find_node(__h->_M_buckets[__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 |
| { |
| 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())); |
| } |
| }; |
| |
| // 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 and equality comparison function |
| // objects here, for convenience. |
| |
| // Primary template: unused except as a hook for specializations. |
| template<typename _Key, typename _Value, |
| typename _ExtractKey, typename _Equal, |
| 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 _Equal, |
| typename _H1, typename _H2, typename _Hash> |
| struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, |
| _Hash, false> |
| { |
| protected: |
| _Hash_code_base(const _ExtractKey& __ex, const _Equal& __eq, |
| const _H1&, const _H2&, const _Hash& __h) |
| : _M_extract(__ex), _M_eq(__eq), _M_ranged_hash(__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); } |
| |
| bool |
| _M_compare(const _Key& __k, _Hash_code_type, |
| _Hash_node<_Value, false>* __n) const |
| { return _M_eq(__k, _M_extract(__n->_M_v)); } |
| |
| 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_eq, __x._M_eq); |
| std::swap(_M_ranged_hash, __x._M_ranged_hash); |
| } |
| |
| protected: |
| _ExtractKey _M_extract; |
| _Equal _M_eq; |
| _Hash _M_ranged_hash; |
| }; |
| |
| |
| // 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 _Equal, |
| typename _H1, typename _H2, typename _Hash> |
| struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, |
| _Hash, true>; |
| |
| // Specialization: hash function and range-hashing function, no |
| // caching of hash codes. H is provided but ignored. Provides |
| // typedef and accessor required by TR1. |
| template<typename _Key, typename _Value, |
| typename _ExtractKey, typename _Equal, |
| typename _H1, typename _H2> |
| struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, |
| _Default_ranged_hash, false> |
| { |
| typedef _H1 hasher; |
| |
| hasher |
| hash_function() const |
| { return _M_h1; } |
| |
| protected: |
| _Hash_code_base(const _ExtractKey& __ex, const _Equal& __eq, |
| const _H1& __h1, const _H2& __h2, |
| const _Default_ranged_hash&) |
| : _M_extract(__ex), _M_eq(__eq), _M_h1(__h1), _M_h2(__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); } |
| |
| bool |
| _M_compare(const _Key& __k, _Hash_code_type, |
| _Hash_node<_Value, false>* __n) const |
| { return _M_eq(__k, _M_extract(__n->_M_v)); } |
| |
| 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_eq, __x._M_eq); |
| std::swap(_M_h1, __x._M_h1); |
| std::swap(_M_h2, __x._M_h2); |
| } |
| |
| protected: |
| _ExtractKey _M_extract; |
| _Equal _M_eq; |
| _H1 _M_h1; |
| _H2 _M_h2; |
| }; |
| |
| // 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 _Equal, |
| typename _H1, typename _H2> |
| struct _Hash_code_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, |
| _Default_ranged_hash, true> |
| { |
| typedef _H1 hasher; |
| |
| hasher |
| hash_function() const |
| { return _M_h1; } |
| |
| protected: |
| _Hash_code_base(const _ExtractKey& __ex, const _Equal& __eq, |
| const _H1& __h1, const _H2& __h2, |
| const _Default_ranged_hash&) |
| : _M_extract(__ex), _M_eq(__eq), _M_h1(__h1), _M_h2(__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); } |
| |
| bool |
| _M_compare(const _Key& __k, _Hash_code_type __c, |
| _Hash_node<_Value, true>* __n) const |
| { return __c == __n->_M_hash_code && _M_eq(__k, _M_extract(__n->_M_v)); } |
| |
| 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_eq, __x._M_eq); |
| std::swap(_M_h1, __x._M_h1); |
| std::swap(_M_h2, __x._M_h2); |
| } |
| |
| protected: |
| _ExtractKey _M_extract; |
| _Equal _M_eq; |
| _H1 _M_h1; |
| _H2 _M_h2; |
| }; |
| |
| |
| // 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 |
