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

//

// (C) Copyright Ion Gaztanaga  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_TREE_NODE_HPP

#define BOOST_INTRUSIVE_TREE_NODE_HPP



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

#include <iterator>

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

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



namespace boost {

namespace intrusive {



template<class VoidPointer>

struct tree_node

{

   typedef typename pointer_to_other

      <VoidPointer

      ,tree_node<VoidPointer> >::type   node_ptr;



   node_ptr parent_, left_, right_;

};



template<class VoidPointer>

struct tree_node_traits

{

   typedef tree_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_parent(const_node_ptr n)

   {  return n->parent_;  }



   static void set_parent(node_ptr n, node_ptr p)

   {  n->parent_ = p;  }



   static node_ptr get_left(const_node_ptr n)

   {  return n->left_;  }



   static void set_left(node_ptr n, node_ptr l)

   {  n->left_ = l;  }



   static node_ptr get_right(const_node_ptr n)

   {  return n->right_;  }



   static void set_right(node_ptr n, node_ptr r)

   {  n->right_ = r;  }

};



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

//                                                                         //

//                   Implementation of the tree iterator                   //

//                                                                         //

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



// tree_iterator provides some basic functions for a 

// node oriented bidirectional iterator:

template<class Container, bool IsConst>

class tree_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 Container::node_algorithms     node_algorithms;

   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:

   public:

   typedef typename detail::add_const_if_c

      <typename Container::value_type, IsConst>

      ::type                                       value_type;

   typedef value_type & reference;

   typedef value_type * pointer;



   tree_iterator()

      : members_ (0, 0)

   {}



   explicit tree_iterator(node_ptr node, const Container *cont_ptr)

      : members_ (node, cont_ptr)

   {}



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

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

   {}



   const node_ptr &pointed_node() const

   { return members_.nodeptr_; }



   tree_iterator &operator=(const node_ptr &node)

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



   public:

   tree_iterator& operator++() 

   { 

      members_.nodeptr_ = node_algorithms::next_node(members_.nodeptr_); 

      return static_cast<tree_iterator&> (*this); 

   }

   

   tree_iterator operator++(int)

   {

      tree_iterator result (*this);

      members_.nodeptr_ = node_algorithms::next_node(members_.nodeptr_);

      return result;

   }



   tree_iterator& operator--() 

   { 

      members_.nodeptr_ = node_algorithms::prev_node(members_.nodeptr_); 

      return static_cast<tree_iterator&> (*this); 

   }

   

   tree_iterator operator--(int)

   {

      tree_iterator result (*this);

      members_.nodeptr_ = node_algorithms::prev_node(members_.nodeptr_);

      return result;

   }



   bool operator== (const tree_iterator& i) const

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



   bool operator!= (const tree_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)

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

      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_TREE_NODE_HPP

