/////////////////////////////////////////////////////////////////////////////

//

// (C) Copyright Olaf Krzikalla 2004-2006.

// (C) Copyright Ion Gaztanaga  2006-2007

//

// 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/intrusive for documentation.

//

/////////////////////////////////////////////////////////////////////////////



#ifndef BOOST_INTRUSIVE_LIST_NODE_HPP

#define BOOST_INTRUSIVE_LIST_NODE_HPP



#include <boost/intrusive/detail/config_begin.hpp>

#include <iterator>

#include <boost/intrusive/detail/assert.hpp>

#include <boost/intrusive/detail/pointer_to_other.hpp>

#include <boost/intrusive/circular_list_algorithms.hpp>



namespace boost {

namespace intrusive {



// list_node_traits can be used with circular_list_algorithms and supplies

// a list_node holding the pointers needed for a double-linked list

// it is used by list_derived_node and list_member_node



template<class VoidPointer>

struct list_node

{

   typedef typename boost::pointer_to_other

      <VoidPointer, list_node>::type   node_ptr;

   node_ptr prev_, next_;

};



template<class VoidPointer>

struct list_node_traits

{

   typedef list_node<VoidPointer> node;

   typedef typename boost::pointer_to_other

      <VoidPointer, node>::type          node_ptr;

   typedef typename boost::pointer_to_other

      <VoidPointer, const node>::type    const_node_ptr;



   static node_ptr get_previous(const_node_ptr n)

   {  return n->prev_;  }



   static void set_previous(node_ptr n, node_ptr prev)

   {  n->prev_ = prev;  }



   static node_ptr get_next(const_node_ptr n)

   {  return n->next_;  }



   static void set_next(node_ptr n, node_ptr next)

   {  n->next_ = next;  }

};



// list_iterator provides some basic functions for a 

// node oriented bidirectional iterator:

template<class Container, bool IsConst>

class list_iterator

   :  public std::iterator

         < std::bidirectional_iterator_tag

         , typename detail::add_const_if_c

            <typename Container::value_type, IsConst>::type

         >

{

   protected:

   typedef typename Container::real_value_traits   real_value_traits;

   typedef typename real_value_traits::node_traits node_traits;

   typedef typename node_traits::node              node;

   typedef typename node_traits::node_ptr          node_ptr;

   typedef typename boost::pointer_to_other

      <node_ptr, void>::type                       void_pointer;

   static const bool store_container_ptr = 

      detail::store_cont_ptr_on_it<Container>::value;



   public:

   typedef typename detail::add_const_if_c

      <typename Container::value_type, IsConst>

      ::type                                       value_type;

   typedef value_type & reference;

   typedef value_type * pointer;



   list_iterator()

      : members_ (0, 0)

   {}



   explicit list_iterator(node_ptr node, const Container *cont_ptr)

      : members_ (node, cont_ptr)

   {}



   list_iterator(list_iterator<Container, false> const& other)

      :  members_(other.pointed_node(), other.get_container())

   {}



   const node_ptr &pointed_node() const

   { return members_.nodeptr_; }



   list_iterator &operator=(const node_ptr &node)

   {  members_.nodeptr_ = node;  return static_cast<list_iterator&>(*this);  }



   public:

   list_iterator& operator++() 

   { 

      members_.nodeptr_ = node_traits::get_next(members_.nodeptr_); 

      return static_cast<list_iterator&> (*this); 

   }

   

   list_iterator operator++(int)

   {

      list_iterator result (*this);

      members_.nodeptr_ = node_traits::get_next(members_.nodeptr_);

      return result;

   }



   list_iterator& operator--() 

   { 

      members_.nodeptr_ = node_traits::get_previous(members_.nodeptr_); 

      return static_cast<list_iterator&> (*this); 

   }

   

   list_iterator operator--(int)

   {

      list_iterator result (*this);

      members_.nodeptr_ = node_traits::get_previous(members_.nodeptr_);

      return result;

   }



   bool operator== (const list_iterator& i) const

   {  return members_.nodeptr_ == i.pointed_node();   }



   bool operator!= (const list_iterator& i) const

   {  return !operator== (i); }



   value_type& operator*() const

   {  return *operator->();   }



   pointer operator->() const

   { return detail::get_pointer(this->get_real_value_traits()->to_value_ptr(members_.nodeptr_)); }



   const Container *get_container() const

   {

      if(store_container_ptr){

         const Container* c = static_cast<const Container*>(members_.get_ptr());

         BOOST_INTRUSIVE_INVARIANT_ASSERT(c != 0);

         return c;

      }

      else{

         return 0;

      }

   }



   const real_value_traits *get_real_value_traits() const

   {

      if(store_container_ptr)

         return &this->get_container()->get_real_value_traits();

      else

         return 0;

   }



   private:

   struct members

      :  public detail::select_constptr

         <void_pointer, store_container_ptr>::type

   {

      typedef typename detail::select_constptr

         <void_pointer, store_container_ptr>::type Base;



      members(const node_ptr &n_ptr, const void *cont)

         :  Base(cont), nodeptr_(n_ptr)

      {}



      node_ptr nodeptr_;

   } members_;

};



} //namespace intrusive 

} //namespace boost 



#include <boost/intrusive/detail/config_end.hpp>



#endif //BOOST_INTRUSIVE_LIST_NODE_HPP

