seq_index_node.hpp

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/* Copyright 2003-2015 Joaquin M Lopez Munoz.
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE_1_0.txt or copy at
 * http://www.boost.org/LICENSE_1_0.txt)
 *
 * See http://www.boost.org/libs/multi_index for library home page.
 */
 
#ifndef BOOST_MULTI_INDEX_DETAIL_SEQ_INDEX_NODE_HPP
#define BOOST_MULTI_INDEX_DETAIL_SEQ_INDEX_NODE_HPP
 
#if defined(_MSC_VER)
#pragma once
#endif
 
#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
#include <algorithm>
#include <boost/detail/allocator_utilities.hpp>
#include <boost/multi_index/detail/raw_ptr.hpp>
 
namespace boost{
 
namespace multi_index{
 
namespace detail{
 
/* doubly-linked node for use by sequenced_index */
 
template<typename Allocator>
struct sequenced_index_node_impl
{
  typedef typename
  boost::detail::allocator::rebind_to<
    Allocator,sequenced_index_node_impl
  >::type::pointer                      pointer;
  typedef typename
  boost::detail::allocator::rebind_to<
    Allocator,sequenced_index_node_impl
  >::type::const_pointer                const_pointer;
 
  pointer& prior(){return prior_;}
  pointer  prior()const{return prior_;}
  pointer& next(){return next_;}
  pointer  next()const{return next_;}
 
  /* interoperability with bidir_node_iterator */
 
  static void increment(pointer& x){x=x->next();}
  static void decrement(pointer& x){x=x->prior();}
 
  /* algorithmic stuff */
 
  static void link(pointer x,pointer header)
  {
    x->prior()=header->prior();
    x->next()=header;
    x->prior()->next()=x->next()->prior()=x;
  };
 
  static void unlink(pointer x)
  {
    x->prior()->next()=x->next();
    x->next()->prior()=x->prior();
  }
 
  static void relink(pointer position,pointer x)
  {
    unlink(x);
    x->prior()=position->prior();
    x->next()=position;
    x->prior()->next()=x->next()->prior()=x;
  }
 
  static void relink(pointer position,pointer x,pointer y)
  {
    /* position is assumed not to be in [x,y) */
 
    if(x!=y){
      pointer z=y->prior();
      x->prior()->next()=y;
      y->prior()=x->prior();
      x->prior()=position->prior();
      z->next()=position;
      x->prior()->next()=x;
      z->next()->prior()=z;
    }
  }
 
  static void reverse(pointer header)
  {
    pointer x=header;
    do{
      pointer y=x->next();
      std::swap(x->prior(),x->next());
      x=y;
    }while(x!=header);
  }
 
  static void swap(pointer x,pointer y)
  {
    /* This swap function does not exchange the header nodes,
     * but rather their pointers. This is *not* used for implementing
     * sequenced_index::swap.
     */
 
    if(x->next()!=x){
      if(y->next()!=y){
        std::swap(x->next(),y->next());
        std::swap(x->prior(),y->prior());
        x->next()->prior()=x->prior()->next()=x;
        y->next()->prior()=y->prior()->next()=y;
      }
      else{
        y->next()=x->next();
        y->prior()=x->prior();
        x->next()=x->prior()=x;
        y->next()->prior()=y->prior()->next()=y;
      }
    }
    else if(y->next()!=y){
      x->next()=y->next();
      x->prior()=y->prior();
      y->next()=y->prior()=y;
      x->next()->prior()=x->prior()->next()=x;
    }
  }
 
private:
  pointer prior_;
  pointer next_;
};
 
template<typename Super>
struct sequenced_index_node_trampoline:
  sequenced_index_node_impl<
    typename boost::detail::allocator::rebind_to<
      typename Super::allocator_type,
      char
    >::type
  >
{
  typedef sequenced_index_node_impl<
    typename boost::detail::allocator::rebind_to<
      typename Super::allocator_type,
      char
    >::type
  > impl_type;
};
 
template<typename Super>
struct sequenced_index_node:Super,sequenced_index_node_trampoline<Super>
{
private:
  typedef sequenced_index_node_trampoline<Super> trampoline;
 
public:
  typedef typename trampoline::impl_type         impl_type;
  typedef typename trampoline::pointer           impl_pointer;
  typedef typename trampoline::const_pointer     const_impl_pointer;
 
  impl_pointer& prior(){return trampoline::prior();}
  impl_pointer  prior()const{return trampoline::prior();}
  impl_pointer& next(){return trampoline::next();}
  impl_pointer  next()const{return trampoline::next();}
 
  impl_pointer impl()
  {
    return static_cast<impl_pointer>(
      static_cast<impl_type*>(static_cast<trampoline*>(this)));
  }
 
  const_impl_pointer impl()const
  {
    return static_cast<const_impl_pointer>(
      static_cast<const impl_type*>(static_cast<const trampoline*>(this)));
  }
 
  static sequenced_index_node* from_impl(impl_pointer x)
  {
    return
      static_cast<sequenced_index_node*>(
        static_cast<trampoline*>(
          raw_ptr<impl_type*>(x)));
  }
 
  static const sequenced_index_node* from_impl(const_impl_pointer x)
  {
    return
      static_cast<const sequenced_index_node*>(
        static_cast<const trampoline*>(
          raw_ptr<const impl_type*>(x)));
  }
 
  /* interoperability with bidir_node_iterator */
 
  static void increment(sequenced_index_node*& x)
  {
    impl_pointer xi=x->impl();
    trampoline::increment(xi);
    x=from_impl(xi);
  }
 
  static void decrement(sequenced_index_node*& x)
  {
    impl_pointer xi=x->impl();
    trampoline::decrement(xi);
    x=from_impl(xi);
  }
};
 
} /* namespace multi_index::detail */
 
} /* namespace multi_index */
 
} /* namespace boost */
 
#endif