728 lines
30 KiB
Plaintext
728 lines
30 KiB
Plaintext
/////////////////////////////////////////////////////////////////////////////
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//
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// (C) Copyright Daniel K. O. 2005.
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// (C) Copyright Ion Gaztanaga 2007-2014
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/intrusive for documentation.
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//
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/////////////////////////////////////////////////////////////////////////////
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#ifndef BOOST_INTRUSIVE_AVLTREE_ALGORITHMS_HPP
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#define BOOST_INTRUSIVE_AVLTREE_ALGORITHMS_HPP
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#include <boost/intrusive/detail/config_begin.hpp>
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#include <boost/intrusive/intrusive_fwd.hpp>
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#include <cstddef>
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#include <boost/intrusive/detail/assert.hpp>
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#include <boost/intrusive/detail/algo_type.hpp>
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#include <boost/intrusive/detail/ebo_functor_holder.hpp>
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#include <boost/intrusive/bstree_algorithms.hpp>
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#if defined(BOOST_HAS_PRAGMA_ONCE)
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# pragma once
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#endif
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namespace boost {
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namespace intrusive {
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/// @cond
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template<class NodeTraits, class F>
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struct avltree_node_cloner
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//Use public inheritance to avoid MSVC bugs with closures
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: public detail::ebo_functor_holder<F>
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{
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typedef typename NodeTraits::node_ptr node_ptr;
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typedef detail::ebo_functor_holder<F> base_t;
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avltree_node_cloner(F f)
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: base_t(f)
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{}
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node_ptr operator()(const node_ptr & p)
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{
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node_ptr n = base_t::get()(p);
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NodeTraits::set_balance(n, NodeTraits::get_balance(p));
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return n;
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}
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node_ptr operator()(const node_ptr & p) const
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{
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node_ptr n = base_t::get()(p);
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NodeTraits::set_balance(n, NodeTraits::get_balance(p));
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return n;
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}
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};
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namespace detail {
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template<class ValueTraits, class NodePtrCompare, class ExtraChecker>
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struct avltree_node_checker
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: public bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker>
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{
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typedef bstree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> base_checker_t;
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typedef ValueTraits value_traits;
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typedef typename value_traits::node_traits node_traits;
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typedef typename node_traits::const_node_ptr const_node_ptr;
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struct return_type
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: public base_checker_t::return_type
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{
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return_type() : height(0) {}
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int height;
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};
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avltree_node_checker(const NodePtrCompare& comp, ExtraChecker extra_checker)
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: base_checker_t(comp, extra_checker)
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{}
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void operator () (const const_node_ptr& p,
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const return_type& check_return_left, const return_type& check_return_right,
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return_type& check_return)
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{
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const int height_diff = check_return_right.height - check_return_left.height; (void)height_diff;
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BOOST_INTRUSIVE_INVARIANT_ASSERT(
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(height_diff == -1 && node_traits::get_balance(p) == node_traits::negative()) ||
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(height_diff == 0 && node_traits::get_balance(p) == node_traits::zero()) ||
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(height_diff == 1 && node_traits::get_balance(p) == node_traits::positive())
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);
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check_return.height = 1 +
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(check_return_left.height > check_return_right.height ? check_return_left.height : check_return_right.height);
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base_checker_t::operator()(p, check_return_left, check_return_right, check_return);
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}
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};
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} // namespace detail
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/// @endcond
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//! avltree_algorithms is configured with a NodeTraits class, which encapsulates the
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//! information about the node to be manipulated. NodeTraits must support the
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//! following interface:
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//!
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//! <b>Typedefs</b>:
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//!
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//! <tt>node</tt>: The type of the node that forms the binary search tree
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//!
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//! <tt>node_ptr</tt>: A pointer to a node
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//!
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//! <tt>const_node_ptr</tt>: A pointer to a const node
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//!
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//! <tt>balance</tt>: The type of the balance factor
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//!
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//! <b>Static functions</b>:
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//!
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//! <tt>static node_ptr get_parent(const_node_ptr n);</tt>
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//!
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//! <tt>static void set_parent(node_ptr n, node_ptr parent);</tt>
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//!
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//! <tt>static node_ptr get_left(const_node_ptr n);</tt>
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//!
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//! <tt>static void set_left(node_ptr n, node_ptr left);</tt>
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//!
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//! <tt>static node_ptr get_right(const_node_ptr n);</tt>
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//!
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//! <tt>static void set_right(node_ptr n, node_ptr right);</tt>
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//!
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//! <tt>static balance get_balance(const_node_ptr n);</tt>
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//!
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//! <tt>static void set_balance(node_ptr n, balance b);</tt>
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//!
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//! <tt>static balance negative();</tt>
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//!
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//! <tt>static balance zero();</tt>
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//!
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//! <tt>static balance positive();</tt>
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template<class NodeTraits>
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class avltree_algorithms
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#ifndef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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: public bstree_algorithms<NodeTraits>
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#endif
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{
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public:
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typedef typename NodeTraits::node node;
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typedef NodeTraits node_traits;
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typedef typename NodeTraits::node_ptr node_ptr;
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typedef typename NodeTraits::const_node_ptr const_node_ptr;
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typedef typename NodeTraits::balance balance;
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/// @cond
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private:
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typedef bstree_algorithms<NodeTraits> bstree_algo;
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/// @endcond
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public:
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//! This type is the information that will be
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//! filled by insert_unique_check
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typedef typename bstree_algo::insert_commit_data insert_commit_data;
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#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::get_header(const const_node_ptr&)
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static node_ptr get_header(const const_node_ptr & n);
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//! @copydoc ::boost::intrusive::bstree_algorithms::begin_node
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static node_ptr begin_node(const const_node_ptr & header);
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//! @copydoc ::boost::intrusive::bstree_algorithms::end_node
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static node_ptr end_node(const const_node_ptr & header);
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//! @copydoc ::boost::intrusive::bstree_algorithms::swap_tree
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static void swap_tree(const node_ptr & header1, const node_ptr & header2);
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#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&)
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static void swap_nodes(const node_ptr & node1, const node_ptr & node2)
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{
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if(node1 == node2)
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return;
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node_ptr header1(bstree_algo::get_header(node1)), header2(bstree_algo::get_header(node2));
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swap_nodes(node1, header1, node2, header2);
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::swap_nodes(const node_ptr&,const node_ptr&,const node_ptr&,const node_ptr&)
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static void swap_nodes(const node_ptr & node1, const node_ptr & header1, const node_ptr & node2, const node_ptr & header2)
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{
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if(node1 == node2) return;
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bstree_algo::swap_nodes(node1, header1, node2, header2);
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//Swap balance
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balance c = NodeTraits::get_balance(node1);
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NodeTraits::set_balance(node1, NodeTraits::get_balance(node2));
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NodeTraits::set_balance(node2, c);
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&)
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static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & new_node)
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{
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if(node_to_be_replaced == new_node)
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return;
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replace_node(node_to_be_replaced, bstree_algo::get_header(node_to_be_replaced), new_node);
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::replace_node(const node_ptr&,const node_ptr&,const node_ptr&)
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static void replace_node(const node_ptr & node_to_be_replaced, const node_ptr & header, const node_ptr & new_node)
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{
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bstree_algo::replace_node(node_to_be_replaced, header, new_node);
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NodeTraits::set_balance(new_node, NodeTraits::get_balance(node_to_be_replaced));
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::unlink(const node_ptr&)
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static void unlink(const node_ptr & node)
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{
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node_ptr x = NodeTraits::get_parent(node);
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if(x){
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while(!is_header(x))
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x = NodeTraits::get_parent(x);
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erase(x, node);
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}
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}
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#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::unlink_leftmost_without_rebalance
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static node_ptr unlink_leftmost_without_rebalance(const node_ptr & header);
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//! @copydoc ::boost::intrusive::bstree_algorithms::unique(const const_node_ptr&)
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static bool unique(const const_node_ptr & node);
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//! @copydoc ::boost::intrusive::bstree_algorithms::size(const const_node_ptr&)
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static std::size_t size(const const_node_ptr & header);
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//! @copydoc ::boost::intrusive::bstree_algorithms::next_node(const node_ptr&)
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static node_ptr next_node(const node_ptr & node);
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//! @copydoc ::boost::intrusive::bstree_algorithms::prev_node(const node_ptr&)
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static node_ptr prev_node(const node_ptr & node);
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//! @copydoc ::boost::intrusive::bstree_algorithms::init(const node_ptr&)
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static void init(const node_ptr & node);
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#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! <b>Requires</b>: node must not be part of any tree.
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//!
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//! <b>Effects</b>: Initializes the header to represent an empty tree.
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//! unique(header) == true.
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//!
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//! <b>Complexity</b>: Constant.
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//!
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//! <b>Throws</b>: Nothing.
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//!
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//! <b>Nodes</b>: If node is inserted in a tree, this function corrupts the tree.
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static void init_header(const node_ptr & header)
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{
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bstree_algo::init_header(header);
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NodeTraits::set_balance(header, NodeTraits::zero());
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::erase(const node_ptr&,const node_ptr&)
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static node_ptr erase(const node_ptr & header, const node_ptr & z)
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{
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typename bstree_algo::data_for_rebalance info;
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bstree_algo::erase(header, z, info);
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rebalance_after_erasure(header, z, info);
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return z;
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::transfer_unique
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template<class NodePtrCompare>
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static bool transfer_unique
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(const node_ptr & header1, NodePtrCompare comp, const node_ptr &header2, const node_ptr & z)
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{
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typename bstree_algo::data_for_rebalance info;
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bool const transferred = bstree_algo::transfer_unique(header1, comp, header2, z, info);
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if(transferred){
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rebalance_after_erasure(header2, z, info);
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rebalance_after_insertion(header1, z);
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}
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return transferred;
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::transfer_equal
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template<class NodePtrCompare>
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static void transfer_equal
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(const node_ptr & header1, NodePtrCompare comp, const node_ptr &header2, const node_ptr & z)
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{
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typename bstree_algo::data_for_rebalance info;
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bstree_algo::transfer_equal(header1, comp, header2, z, info);
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rebalance_after_erasure(header2, z, info);
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rebalance_after_insertion(header1, z);
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::clone(const const_node_ptr&,const node_ptr&,Cloner,Disposer)
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template <class Cloner, class Disposer>
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static void clone
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(const const_node_ptr & source_header, const node_ptr & target_header, Cloner cloner, Disposer disposer)
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{
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avltree_node_cloner<NodeTraits, Cloner> new_cloner(cloner);
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bstree_algo::clone(source_header, target_header, new_cloner, disposer);
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}
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#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::clear_and_dispose(const node_ptr&,Disposer)
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template<class Disposer>
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static void clear_and_dispose(const node_ptr & header, Disposer disposer);
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//! @copydoc ::boost::intrusive::bstree_algorithms::lower_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
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template<class KeyType, class KeyNodePtrCompare>
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static node_ptr lower_bound
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(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
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//! @copydoc ::boost::intrusive::bstree_algorithms::upper_bound(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
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template<class KeyType, class KeyNodePtrCompare>
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static node_ptr upper_bound
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(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
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//! @copydoc ::boost::intrusive::bstree_algorithms::find(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
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template<class KeyType, class KeyNodePtrCompare>
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static node_ptr find
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(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
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//! @copydoc ::boost::intrusive::bstree_algorithms::equal_range(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
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template<class KeyType, class KeyNodePtrCompare>
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static std::pair<node_ptr, node_ptr> equal_range
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(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
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//! @copydoc ::boost::intrusive::bstree_algorithms::bounded_range(const const_node_ptr&,const KeyType&,const KeyType&,KeyNodePtrCompare,bool,bool)
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template<class KeyType, class KeyNodePtrCompare>
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static std::pair<node_ptr, node_ptr> bounded_range
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(const const_node_ptr & header, const KeyType &lower_key, const KeyType &upper_key, KeyNodePtrCompare comp
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, bool left_closed, bool right_closed);
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//! @copydoc ::boost::intrusive::bstree_algorithms::count(const const_node_ptr&,const KeyType&,KeyNodePtrCompare)
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template<class KeyType, class KeyNodePtrCompare>
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static std::size_t count(const const_node_ptr & header, const KeyType &key, KeyNodePtrCompare comp);
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#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_upper_bound(const node_ptr&,const node_ptr&,NodePtrCompare)
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template<class NodePtrCompare>
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static node_ptr insert_equal_upper_bound
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(const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp)
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{
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bstree_algo::insert_equal_upper_bound(h, new_node, comp);
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rebalance_after_insertion(h, new_node);
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return new_node;
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal_lower_bound(const node_ptr&,const node_ptr&,NodePtrCompare)
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template<class NodePtrCompare>
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static node_ptr insert_equal_lower_bound
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(const node_ptr & h, const node_ptr & new_node, NodePtrCompare comp)
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{
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bstree_algo::insert_equal_lower_bound(h, new_node, comp);
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rebalance_after_insertion(h, new_node);
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return new_node;
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_equal(const node_ptr&,const node_ptr&,const node_ptr&,NodePtrCompare)
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template<class NodePtrCompare>
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static node_ptr insert_equal
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(const node_ptr & header, const node_ptr & hint, const node_ptr & new_node, NodePtrCompare comp)
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{
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bstree_algo::insert_equal(header, hint, new_node, comp);
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rebalance_after_insertion(header, new_node);
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return new_node;
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_before(const node_ptr&,const node_ptr&,const node_ptr&)
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static node_ptr insert_before
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(const node_ptr & header, const node_ptr & pos, const node_ptr & new_node)
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{
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bstree_algo::insert_before(header, pos, new_node);
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rebalance_after_insertion(header, new_node);
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return new_node;
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::push_back(const node_ptr&,const node_ptr&)
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static void push_back(const node_ptr & header, const node_ptr & new_node)
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{
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bstree_algo::push_back(header, new_node);
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rebalance_after_insertion(header, new_node);
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::push_front(const node_ptr&,const node_ptr&)
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static void push_front(const node_ptr & header, const node_ptr & new_node)
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{
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bstree_algo::push_front(header, new_node);
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rebalance_after_insertion(header, new_node);
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}
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#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
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template<class KeyType, class KeyNodePtrCompare>
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static std::pair<node_ptr, bool> insert_unique_check
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(const const_node_ptr & header, const KeyType &key
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,KeyNodePtrCompare comp, insert_commit_data &commit_data);
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_check(const const_node_ptr&,const node_ptr&,const KeyType&,KeyNodePtrCompare,insert_commit_data&)
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template<class KeyType, class KeyNodePtrCompare>
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static std::pair<node_ptr, bool> insert_unique_check
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(const const_node_ptr & header, const node_ptr &hint, const KeyType &key
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,KeyNodePtrCompare comp, insert_commit_data &commit_data);
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#endif //#ifdef BOOST_INTRUSIVE_DOXYGEN_INVOKED
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//! @copydoc ::boost::intrusive::bstree_algorithms::insert_unique_commit(const node_ptr&,const node_ptr&,const insert_commit_data &)
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static void insert_unique_commit
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(const node_ptr & header, const node_ptr & new_value, const insert_commit_data &commit_data)
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{
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bstree_algo::insert_unique_commit(header, new_value, commit_data);
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rebalance_after_insertion(header, new_value);
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}
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//! @copydoc ::boost::intrusive::bstree_algorithms::is_header
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static bool is_header(const const_node_ptr & p)
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{ return NodeTraits::get_balance(p) == NodeTraits::zero() && bstree_algo::is_header(p); }
|
|
|
|
|
|
/// @cond
|
|
static bool verify(const node_ptr &header)
|
|
{
|
|
std::size_t height;
|
|
std::size_t count;
|
|
return verify_recursion(NodeTraits::get_parent(header), count, height);
|
|
}
|
|
|
|
private:
|
|
|
|
static bool verify_recursion(node_ptr n, std::size_t &count, std::size_t &height)
|
|
{
|
|
if (!n){
|
|
count = 0;
|
|
height = 0;
|
|
return true;
|
|
}
|
|
std::size_t leftcount, rightcount;
|
|
std::size_t leftheight, rightheight;
|
|
if(!verify_recursion(NodeTraits::get_left (n), leftcount, leftheight) ||
|
|
!verify_recursion(NodeTraits::get_right(n), rightcount, rightheight) ){
|
|
return false;
|
|
}
|
|
count = 1u + leftcount + rightcount;
|
|
height = 1u + (leftheight > rightheight ? leftheight : rightheight);
|
|
|
|
//If equal height, balance must be zero
|
|
if(rightheight == leftheight){
|
|
if(NodeTraits::get_balance(n) != NodeTraits::zero()){
|
|
BOOST_ASSERT(0);
|
|
return false;
|
|
}
|
|
}
|
|
//If right is taller than left, then the difference must be at least 1 and the balance positive
|
|
else if(rightheight > leftheight){
|
|
if(rightheight - leftheight > 1 ){
|
|
BOOST_ASSERT(0);
|
|
return false;
|
|
}
|
|
else if(NodeTraits::get_balance(n) != NodeTraits::positive()){
|
|
BOOST_ASSERT(0);
|
|
return false;
|
|
}
|
|
}
|
|
//If left is taller than right, then the difference must be at least 1 and the balance negative
|
|
else{
|
|
if(leftheight - rightheight > 1 ){
|
|
BOOST_ASSERT(0);
|
|
return false;
|
|
}
|
|
else if(NodeTraits::get_balance(n) != NodeTraits::negative()){
|
|
BOOST_ASSERT(0);
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static void rebalance_after_erasure
|
|
( const node_ptr & header, const node_ptr &z, const typename bstree_algo::data_for_rebalance &info)
|
|
{
|
|
if(info.y != z){
|
|
NodeTraits::set_balance(info.y, NodeTraits::get_balance(z));
|
|
}
|
|
//Rebalance avltree
|
|
rebalance_after_erasure_restore_invariants(header, info.x, info.x_parent);
|
|
}
|
|
|
|
static void rebalance_after_erasure_restore_invariants(const node_ptr & header, node_ptr x, node_ptr x_parent)
|
|
{
|
|
for ( node_ptr root = NodeTraits::get_parent(header)
|
|
; x != root
|
|
; root = NodeTraits::get_parent(header), x_parent = NodeTraits::get_parent(x)) {
|
|
const balance x_parent_balance = NodeTraits::get_balance(x_parent);
|
|
//Don't cache x_is_leftchild or similar because x can be null and
|
|
//equal to both x_parent_left and x_parent_right
|
|
const node_ptr x_parent_left (NodeTraits::get_left(x_parent));
|
|
const node_ptr x_parent_right(NodeTraits::get_right(x_parent));
|
|
|
|
if(x_parent_balance == NodeTraits::zero()){
|
|
NodeTraits::set_balance( x_parent, x == x_parent_right ? NodeTraits::negative() : NodeTraits::positive() );
|
|
break; // the height didn't change, let's stop here
|
|
}
|
|
else if(x_parent_balance == NodeTraits::negative()){
|
|
if (x == x_parent_left) { ////x is left child or x and sibling are null
|
|
NodeTraits::set_balance(x_parent, NodeTraits::zero()); // balanced
|
|
x = x_parent;
|
|
}
|
|
else {
|
|
// x is right child (x_parent_left is the left child)
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(x_parent_left);
|
|
if (NodeTraits::get_balance(x_parent_left) == NodeTraits::positive()) {
|
|
// x_parent_left MUST have a right child
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(NodeTraits::get_right(x_parent_left));
|
|
x = avl_rotate_left_right(x_parent, x_parent_left, header);
|
|
}
|
|
else {
|
|
avl_rotate_right(x_parent, x_parent_left, header);
|
|
x = x_parent_left;
|
|
}
|
|
|
|
// if changed from negative to NodeTraits::positive(), no need to check above
|
|
if (NodeTraits::get_balance(x) == NodeTraits::positive()){
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if(x_parent_balance == NodeTraits::positive()){
|
|
if (x == x_parent_right) { //x is right child or x and sibling are null
|
|
NodeTraits::set_balance(x_parent, NodeTraits::zero()); // balanced
|
|
x = x_parent;
|
|
}
|
|
else {
|
|
// x is left child (x_parent_right is the right child)
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(x_parent_right);
|
|
if (NodeTraits::get_balance(x_parent_right) == NodeTraits::negative()) {
|
|
// x_parent_right MUST have then a left child
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(NodeTraits::get_left(x_parent_right));
|
|
x = avl_rotate_right_left(x_parent, x_parent_right, header);
|
|
}
|
|
else {
|
|
avl_rotate_left(x_parent, x_parent_right, header);
|
|
x = x_parent_right;
|
|
}
|
|
// if changed from NodeTraits::positive() to negative, no need to check above
|
|
if (NodeTraits::get_balance(x) == NodeTraits::negative()){
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else{
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(false); // never reached
|
|
}
|
|
}
|
|
}
|
|
|
|
static void rebalance_after_insertion(const node_ptr & header, node_ptr x)
|
|
{
|
|
NodeTraits::set_balance(x, NodeTraits::zero());
|
|
// Rebalance.
|
|
for(node_ptr root = NodeTraits::get_parent(header); x != root; root = NodeTraits::get_parent(header)){
|
|
node_ptr const x_parent(NodeTraits::get_parent(x));
|
|
node_ptr const x_parent_left(NodeTraits::get_left(x_parent));
|
|
const balance x_parent_balance = NodeTraits::get_balance(x_parent);
|
|
const bool x_is_leftchild(x == x_parent_left);
|
|
if(x_parent_balance == NodeTraits::zero()){
|
|
// if x is left, parent will have parent->bal_factor = negative
|
|
// else, parent->bal_factor = NodeTraits::positive()
|
|
NodeTraits::set_balance( x_parent, x_is_leftchild ? NodeTraits::negative() : NodeTraits::positive() );
|
|
x = x_parent;
|
|
}
|
|
else if(x_parent_balance == NodeTraits::positive()){
|
|
// if x is a left child, parent->bal_factor = zero
|
|
if (x_is_leftchild)
|
|
NodeTraits::set_balance(x_parent, NodeTraits::zero());
|
|
else{ // x is a right child, needs rebalancing
|
|
if (NodeTraits::get_balance(x) == NodeTraits::negative())
|
|
avl_rotate_right_left(x_parent, x, header);
|
|
else
|
|
avl_rotate_left(x_parent, x, header);
|
|
}
|
|
break;
|
|
}
|
|
else if(x_parent_balance == NodeTraits::negative()){
|
|
// if x is a left child, needs rebalancing
|
|
if (x_is_leftchild) {
|
|
if (NodeTraits::get_balance(x) == NodeTraits::positive())
|
|
avl_rotate_left_right(x_parent, x, header);
|
|
else
|
|
avl_rotate_right(x_parent, x, header);
|
|
}
|
|
else
|
|
NodeTraits::set_balance(x_parent, NodeTraits::zero());
|
|
break;
|
|
}
|
|
else{
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(false); // never reached
|
|
}
|
|
}
|
|
}
|
|
|
|
static void left_right_balancing(const node_ptr & a, const node_ptr & b, const node_ptr & c)
|
|
{
|
|
// balancing...
|
|
const balance c_balance = NodeTraits::get_balance(c);
|
|
const balance zero_balance = NodeTraits::zero();
|
|
const balance posi_balance = NodeTraits::positive();
|
|
const balance nega_balance = NodeTraits::negative();
|
|
NodeTraits::set_balance(c, zero_balance);
|
|
if(c_balance == nega_balance){
|
|
NodeTraits::set_balance(a, posi_balance);
|
|
NodeTraits::set_balance(b, zero_balance);
|
|
}
|
|
else if(c_balance == zero_balance){
|
|
NodeTraits::set_balance(a, zero_balance);
|
|
NodeTraits::set_balance(b, zero_balance);
|
|
}
|
|
else if(c_balance == posi_balance){
|
|
NodeTraits::set_balance(a, zero_balance);
|
|
NodeTraits::set_balance(b, nega_balance);
|
|
}
|
|
else{
|
|
BOOST_INTRUSIVE_INVARIANT_ASSERT(false); // never reached
|
|
}
|
|
}
|
|
|
|
static node_ptr avl_rotate_left_right(const node_ptr a, const node_ptr a_oldleft, const node_ptr & hdr)
|
|
{ // [note: 'a_oldleft' is 'b']
|
|
// | | //
|
|
// a(-2) c //
|
|
// / \ / \ //
|
|
// / \ ==> / \ //
|
|
// (pos)b [g] b a //
|
|
// / \ / \ / \ //
|
|
// [d] c [d] e f [g] //
|
|
// / \ //
|
|
// e f //
|
|
const node_ptr c = NodeTraits::get_right(a_oldleft);
|
|
bstree_algo::rotate_left_no_parent_fix(a_oldleft, c);
|
|
//No need to link c with a [NodeTraits::set_parent(c, a) + NodeTraits::set_left(a, c)]
|
|
//as c is not root and another rotation is coming
|
|
bstree_algo::rotate_right(a, c, NodeTraits::get_parent(a), hdr);
|
|
left_right_balancing(a, a_oldleft, c);
|
|
return c;
|
|
}
|
|
|
|
static node_ptr avl_rotate_right_left(const node_ptr a, const node_ptr a_oldright, const node_ptr & hdr)
|
|
{ // [note: 'a_oldright' is 'b']
|
|
// | | //
|
|
// a(pos) c //
|
|
// / \ / \ //
|
|
// / \ / \ //
|
|
// [d] b(neg) ==> a b //
|
|
// / \ / \ / \ //
|
|
// c [g] [d] e f [g] //
|
|
// / \ //
|
|
// e f //
|
|
const node_ptr c (NodeTraits::get_left(a_oldright));
|
|
bstree_algo::rotate_right_no_parent_fix(a_oldright, c);
|
|
//No need to link c with a [NodeTraits::set_parent(c, a) + NodeTraits::set_right(a, c)]
|
|
//as c is not root and another rotation is coming.
|
|
bstree_algo::rotate_left(a, c, NodeTraits::get_parent(a), hdr);
|
|
left_right_balancing(a_oldright, a, c);
|
|
return c;
|
|
}
|
|
|
|
static void avl_rotate_left(const node_ptr &x, const node_ptr &x_oldright, const node_ptr & hdr)
|
|
{
|
|
bstree_algo::rotate_left(x, x_oldright, NodeTraits::get_parent(x), hdr);
|
|
|
|
// reset the balancing factor
|
|
if (NodeTraits::get_balance(x_oldright) == NodeTraits::positive()) {
|
|
NodeTraits::set_balance(x, NodeTraits::zero());
|
|
NodeTraits::set_balance(x_oldright, NodeTraits::zero());
|
|
}
|
|
else { // this doesn't happen during insertions
|
|
NodeTraits::set_balance(x, NodeTraits::positive());
|
|
NodeTraits::set_balance(x_oldright, NodeTraits::negative());
|
|
}
|
|
}
|
|
|
|
static void avl_rotate_right(const node_ptr &x, const node_ptr &x_oldleft, const node_ptr & hdr)
|
|
{
|
|
bstree_algo::rotate_right(x, x_oldleft, NodeTraits::get_parent(x), hdr);
|
|
|
|
// reset the balancing factor
|
|
if (NodeTraits::get_balance(x_oldleft) == NodeTraits::negative()) {
|
|
NodeTraits::set_balance(x, NodeTraits::zero());
|
|
NodeTraits::set_balance(x_oldleft, NodeTraits::zero());
|
|
}
|
|
else { // this doesn't happen during insertions
|
|
NodeTraits::set_balance(x, NodeTraits::negative());
|
|
NodeTraits::set_balance(x_oldleft, NodeTraits::positive());
|
|
}
|
|
}
|
|
|
|
/// @endcond
|
|
};
|
|
|
|
/// @cond
|
|
|
|
template<class NodeTraits>
|
|
struct get_algo<AvlTreeAlgorithms, NodeTraits>
|
|
{
|
|
typedef avltree_algorithms<NodeTraits> type;
|
|
};
|
|
|
|
template <class ValueTraits, class NodePtrCompare, class ExtraChecker>
|
|
struct get_node_checker<AvlTreeAlgorithms, ValueTraits, NodePtrCompare, ExtraChecker>
|
|
{
|
|
typedef detail::avltree_node_checker<ValueTraits, NodePtrCompare, ExtraChecker> type;
|
|
};
|
|
|
|
/// @endcond
|
|
|
|
} //namespace intrusive
|
|
} //namespace boost
|
|
|
|
#include <boost/intrusive/detail/config_end.hpp>
|
|
|
|
#endif //BOOST_INTRUSIVE_AVLTREE_ALGORITHMS_HPP
|