866 lines
27 KiB
C++
866 lines
27 KiB
C++
// Internal policy header for TR1 unordered_set and unordered_map -*- C++ -*-
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// Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/** @file tr1_impl/hashtable_policy.h
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* This is an internal header file, included by other library headers.
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* You should not attempt to use it directly.
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*/
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namespace std
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{
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_GLIBCXX_BEGIN_NAMESPACE_TR1
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namespace __detail
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{
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// Helper function: return distance(first, last) for forward
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// iterators, or 0 for input iterators.
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template<class _Iterator>
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inline typename std::iterator_traits<_Iterator>::difference_type
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__distance_fw(_Iterator __first, _Iterator __last,
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std::input_iterator_tag)
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{ return 0; }
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template<class _Iterator>
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inline typename std::iterator_traits<_Iterator>::difference_type
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__distance_fw(_Iterator __first, _Iterator __last,
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std::forward_iterator_tag)
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{ return std::distance(__first, __last); }
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template<class _Iterator>
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inline typename std::iterator_traits<_Iterator>::difference_type
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__distance_fw(_Iterator __first, _Iterator __last)
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{
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typedef typename std::iterator_traits<_Iterator>::iterator_category _Tag;
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return __distance_fw(__first, __last, _Tag());
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}
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template<typename _RAIter, typename _Tp>
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_RAIter
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__lower_bound(_RAIter __first, _RAIter __last, const _Tp& __val)
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{
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typedef typename std::iterator_traits<_RAIter>::difference_type _DType;
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_DType __len = __last - __first;
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while (__len > 0)
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{
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_DType __half = __len >> 1;
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_RAIter __middle = __first + __half;
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if (*__middle < __val)
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{
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__first = __middle;
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++__first;
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__len = __len - __half - 1;
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}
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else
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__len = __half;
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}
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return __first;
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}
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// Auxiliary types used for all instantiations of _Hashtable: nodes
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// and iterators.
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// Nodes, used to wrap elements stored in the hash table. A policy
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// template parameter of class template _Hashtable controls whether
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// nodes also store a hash code. In some cases (e.g. strings) this
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// may be a performance win.
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template<typename _Value, bool __cache_hash_code>
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struct _Hash_node;
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template<typename _Value>
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struct _Hash_node<_Value, true>
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{
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_Value _M_v;
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std::size_t _M_hash_code;
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_Hash_node* _M_next;
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#ifdef _GLIBCXX_INCLUDE_AS_CXX0X
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template<typename... _Args>
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_Hash_node(_Args&&... __args)
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: _M_v(std::forward<_Args>(__args)...),
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_M_hash_code(), _M_next() { }
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#endif
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};
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template<typename _Value>
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struct _Hash_node<_Value, false>
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{
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_Value _M_v;
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_Hash_node* _M_next;
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#ifdef _GLIBCXX_INCLUDE_AS_CXX0X
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template<typename... _Args>
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_Hash_node(_Args&&... __args)
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: _M_v(std::forward<_Args>(__args)...),
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_M_next() { }
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#endif
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};
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// Local iterators, used to iterate within a bucket but not between
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// buckets.
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template<typename _Value, bool __cache>
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struct _Node_iterator_base
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{
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_Node_iterator_base(_Hash_node<_Value, __cache>* __p)
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: _M_cur(__p) { }
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void
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_M_incr()
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{ _M_cur = _M_cur->_M_next; }
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_Hash_node<_Value, __cache>* _M_cur;
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};
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template<typename _Value, bool __cache>
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inline bool
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operator==(const _Node_iterator_base<_Value, __cache>& __x,
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const _Node_iterator_base<_Value, __cache>& __y)
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{ return __x._M_cur == __y._M_cur; }
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template<typename _Value, bool __cache>
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inline bool
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operator!=(const _Node_iterator_base<_Value, __cache>& __x,
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const _Node_iterator_base<_Value, __cache>& __y)
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{ return __x._M_cur != __y._M_cur; }
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template<typename _Value, bool __constant_iterators, bool __cache>
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struct _Node_iterator
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: public _Node_iterator_base<_Value, __cache>
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{
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typedef _Value value_type;
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typedef typename
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__gnu_cxx::__conditional_type<__constant_iterators,
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const _Value*, _Value*>::__type
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pointer;
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typedef typename
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__gnu_cxx::__conditional_type<__constant_iterators,
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const _Value&, _Value&>::__type
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reference;
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typedef std::ptrdiff_t difference_type;
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typedef std::forward_iterator_tag iterator_category;
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_Node_iterator()
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: _Node_iterator_base<_Value, __cache>(0) { }
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explicit
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_Node_iterator(_Hash_node<_Value, __cache>* __p)
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: _Node_iterator_base<_Value, __cache>(__p) { }
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reference
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operator*() const
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{ return this->_M_cur->_M_v; }
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pointer
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operator->() const
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{ return &this->_M_cur->_M_v; }
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_Node_iterator&
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operator++()
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{
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this->_M_incr();
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return *this;
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}
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_Node_iterator
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operator++(int)
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{
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_Node_iterator __tmp(*this);
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this->_M_incr();
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return __tmp;
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}
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};
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template<typename _Value, bool __constant_iterators, bool __cache>
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struct _Node_const_iterator
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: public _Node_iterator_base<_Value, __cache>
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{
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typedef _Value value_type;
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typedef const _Value* pointer;
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typedef const _Value& reference;
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typedef std::ptrdiff_t difference_type;
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typedef std::forward_iterator_tag iterator_category;
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_Node_const_iterator()
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: _Node_iterator_base<_Value, __cache>(0) { }
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explicit
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_Node_const_iterator(_Hash_node<_Value, __cache>* __p)
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: _Node_iterator_base<_Value, __cache>(__p) { }
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_Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
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__cache>& __x)
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: _Node_iterator_base<_Value, __cache>(__x._M_cur) { }
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reference
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operator*() const
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{ return this->_M_cur->_M_v; }
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pointer
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operator->() const
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{ return &this->_M_cur->_M_v; }
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_Node_const_iterator&
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operator++()
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{
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this->_M_incr();
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return *this;
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}
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_Node_const_iterator
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operator++(int)
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{
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_Node_const_iterator __tmp(*this);
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this->_M_incr();
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return __tmp;
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}
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};
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template<typename _Value, bool __cache>
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struct _Hashtable_iterator_base
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{
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_Hashtable_iterator_base(_Hash_node<_Value, __cache>* __node,
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_Hash_node<_Value, __cache>** __bucket)
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: _M_cur_node(__node), _M_cur_bucket(__bucket) { }
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void
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_M_incr()
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{
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_M_cur_node = _M_cur_node->_M_next;
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if (!_M_cur_node)
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_M_incr_bucket();
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}
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void
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_M_incr_bucket();
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_Hash_node<_Value, __cache>* _M_cur_node;
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_Hash_node<_Value, __cache>** _M_cur_bucket;
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};
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// Global iterators, used for arbitrary iteration within a hash
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// table. Larger and more expensive than local iterators.
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template<typename _Value, bool __cache>
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void
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_Hashtable_iterator_base<_Value, __cache>::
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_M_incr_bucket()
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{
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++_M_cur_bucket;
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// This loop requires the bucket array to have a non-null sentinel.
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while (!*_M_cur_bucket)
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++_M_cur_bucket;
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_M_cur_node = *_M_cur_bucket;
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}
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template<typename _Value, bool __cache>
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inline bool
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operator==(const _Hashtable_iterator_base<_Value, __cache>& __x,
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const _Hashtable_iterator_base<_Value, __cache>& __y)
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{ return __x._M_cur_node == __y._M_cur_node; }
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template<typename _Value, bool __cache>
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inline bool
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operator!=(const _Hashtable_iterator_base<_Value, __cache>& __x,
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const _Hashtable_iterator_base<_Value, __cache>& __y)
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{ return __x._M_cur_node != __y._M_cur_node; }
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template<typename _Value, bool __constant_iterators, bool __cache>
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struct _Hashtable_iterator
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: public _Hashtable_iterator_base<_Value, __cache>
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{
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typedef _Value value_type;
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typedef typename
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__gnu_cxx::__conditional_type<__constant_iterators,
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const _Value*, _Value*>::__type
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pointer;
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typedef typename
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__gnu_cxx::__conditional_type<__constant_iterators,
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const _Value&, _Value&>::__type
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reference;
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typedef std::ptrdiff_t difference_type;
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typedef std::forward_iterator_tag iterator_category;
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_Hashtable_iterator()
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: _Hashtable_iterator_base<_Value, __cache>(0, 0) { }
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_Hashtable_iterator(_Hash_node<_Value, __cache>* __p,
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_Hash_node<_Value, __cache>** __b)
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: _Hashtable_iterator_base<_Value, __cache>(__p, __b) { }
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explicit
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_Hashtable_iterator(_Hash_node<_Value, __cache>** __b)
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: _Hashtable_iterator_base<_Value, __cache>(*__b, __b) { }
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reference
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operator*() const
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{ return this->_M_cur_node->_M_v; }
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pointer
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operator->() const
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{ return &this->_M_cur_node->_M_v; }
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_Hashtable_iterator&
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operator++()
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{
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this->_M_incr();
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return *this;
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}
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_Hashtable_iterator
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operator++(int)
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{
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_Hashtable_iterator __tmp(*this);
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this->_M_incr();
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return __tmp;
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}
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};
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template<typename _Value, bool __constant_iterators, bool __cache>
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struct _Hashtable_const_iterator
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: public _Hashtable_iterator_base<_Value, __cache>
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{
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typedef _Value value_type;
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typedef const _Value* pointer;
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typedef const _Value& reference;
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typedef std::ptrdiff_t difference_type;
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typedef std::forward_iterator_tag iterator_category;
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_Hashtable_const_iterator()
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: _Hashtable_iterator_base<_Value, __cache>(0, 0) { }
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_Hashtable_const_iterator(_Hash_node<_Value, __cache>* __p,
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_Hash_node<_Value, __cache>** __b)
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: _Hashtable_iterator_base<_Value, __cache>(__p, __b) { }
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explicit
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_Hashtable_const_iterator(_Hash_node<_Value, __cache>** __b)
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: _Hashtable_iterator_base<_Value, __cache>(*__b, __b) { }
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_Hashtable_const_iterator(const _Hashtable_iterator<_Value,
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__constant_iterators, __cache>& __x)
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: _Hashtable_iterator_base<_Value, __cache>(__x._M_cur_node,
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__x._M_cur_bucket) { }
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reference
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operator*() const
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{ return this->_M_cur_node->_M_v; }
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pointer
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operator->() const
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{ return &this->_M_cur_node->_M_v; }
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_Hashtable_const_iterator&
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operator++()
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{
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this->_M_incr();
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return *this;
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}
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_Hashtable_const_iterator
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operator++(int)
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{
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_Hashtable_const_iterator __tmp(*this);
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this->_M_incr();
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return __tmp;
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}
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};
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// Many of class template _Hashtable's template parameters are policy
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// classes. These are defaults for the policies.
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// Default range hashing function: use division to fold a large number
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// into the range [0, N).
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struct _Mod_range_hashing
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{
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typedef std::size_t first_argument_type;
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typedef std::size_t second_argument_type;
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typedef std::size_t result_type;
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result_type
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operator()(first_argument_type __num, second_argument_type __den) const
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{ return __num % __den; }
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};
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// Default ranged hash function H. In principle it should be a
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// function object composed from objects of type H1 and H2 such that
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// h(k, N) = h2(h1(k), N), but that would mean making extra copies of
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// h1 and h2. So instead we'll just use a tag to tell class template
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// hashtable to do that composition.
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struct _Default_ranged_hash { };
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// Default value for rehash policy. Bucket size is (usually) the
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// smallest prime that keeps the load factor small enough.
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struct _Prime_rehash_policy
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{
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_Prime_rehash_policy(float __z = 1.0)
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: _M_max_load_factor(__z), _M_growth_factor(2.f), _M_next_resize(0) { }
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float
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max_load_factor() const
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{ return _M_max_load_factor; }
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// Return a bucket size no smaller than n.
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std::size_t
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_M_next_bkt(std::size_t __n) const;
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// Return a bucket count appropriate for n elements
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std::size_t
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_M_bkt_for_elements(std::size_t __n) const;
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// __n_bkt is current bucket count, __n_elt is current element count,
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// and __n_ins is number of elements to be inserted. Do we need to
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// increase bucket count? If so, return make_pair(true, n), where n
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// is the new bucket count. If not, return make_pair(false, 0).
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std::pair<bool, std::size_t>
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_M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
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std::size_t __n_ins) const;
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enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 };
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float _M_max_load_factor;
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float _M_growth_factor;
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mutable std::size_t _M_next_resize;
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};
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extern const unsigned long __prime_list[];
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// XXX This is a hack. There's no good reason for any of
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// _Prime_rehash_policy's member functions to be inline.
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// Return a prime no smaller than n.
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inline std::size_t
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_Prime_rehash_policy::
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_M_next_bkt(std::size_t __n) const
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{
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const unsigned long* __p = __lower_bound(__prime_list, __prime_list
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+ _S_n_primes, __n);
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_M_next_resize =
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static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor));
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return *__p;
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}
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// Return the smallest prime p such that alpha p >= n, where alpha
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// is the load factor.
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inline std::size_t
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_Prime_rehash_policy::
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_M_bkt_for_elements(std::size_t __n) const
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{
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const float __min_bkts = __n / _M_max_load_factor;
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const unsigned long* __p = __lower_bound(__prime_list, __prime_list
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+ _S_n_primes, __min_bkts);
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_M_next_resize =
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static_cast<std::size_t>(__builtin_ceil(*__p * _M_max_load_factor));
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return *__p;
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}
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// Finds the smallest prime p such that alpha p > __n_elt + __n_ins.
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// If p > __n_bkt, return make_pair(true, p); otherwise return
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// make_pair(false, 0). In principle this isn't very different from
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// _M_bkt_for_elements.
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// The only tricky part is that we're caching the element count at
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// which we need to rehash, so we don't have to do a floating-point
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// multiply for every insertion.
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inline std::pair<bool, std::size_t>
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_Prime_rehash_policy::
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_M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
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std::size_t __n_ins) const
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{
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if (__n_elt + __n_ins > _M_next_resize)
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{
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float __min_bkts = ((float(__n_ins) + float(__n_elt))
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/ _M_max_load_factor);
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if (__min_bkts > __n_bkt)
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{
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__min_bkts = std::max(__min_bkts, _M_growth_factor * __n_bkt);
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const unsigned long* __p =
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__lower_bound(__prime_list, __prime_list + _S_n_primes,
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__min_bkts);
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_M_next_resize = static_cast<std::size_t>
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(__builtin_ceil(*__p * _M_max_load_factor));
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return std::make_pair(true, *__p);
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}
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else
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{
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_M_next_resize = static_cast<std::size_t>
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(__builtin_ceil(__n_bkt * _M_max_load_factor));
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return std::make_pair(false, 0);
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}
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}
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else
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return std::make_pair(false, 0);
|
|
}
|
|
|
|
// Base classes for std::tr1::_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);
|
|
|
|
#ifdef _GLIBCXX_INCLUDE_AS_CXX0X
|
|
// _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;
|
|
#endif
|
|
};
|
|
|
|
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;
|
|
}
|
|
|
|
#ifdef _GLIBCXX_INCLUDE_AS_CXX0X
|
|
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;
|
|
}
|
|
#endif
|
|
|
|
// class template _Rehash_base. Give hashtable the max_load_factor
|
|
// functions 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));
|
|
}
|
|
};
|
|
|
|
// 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;
|
|
};
|
|
} // namespace __detail
|
|
|
|
_GLIBCXX_END_NAMESPACE_TR1
|
|
}
|