Chris@16: //  (C) Copyright Jeremy Siek 1999.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_TREE_STRUCTURE_HPP
Chris@16: #define BOOST_TREE_STRUCTURE_HPP
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16:   template <class T>
Chris@16:   struct tree_traits {
Chris@16:     typedef typename T::node_descriptor node_descriptor;    
Chris@16:     typedef typename T::children_iterator children_iterator;    
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16:   template <class Tree, class TreeVisitor>
Chris@16:   void traverse_tree(typename tree_traits<Tree>::node_descriptor v,
Chris@16:                      Tree& t, TreeVisitor visitor)
Chris@16:   {
Chris@16:     visitor.preorder(v, t);
Chris@16:     typename tree_traits<Tree>::children_iterator i, end;
Chris@16:     boost::tie(i, end) = children(v, t);
Chris@16:     if (i != end) {
Chris@16:       traverse_tree(*i++, t, visitor);
Chris@16:       visitor.inorder(v, t);
Chris@16:       while (i != end)
Chris@16:         traverse_tree(*i++, t, visitor);
Chris@16:     } else
Chris@16:       visitor.inorder(v, t);
Chris@16:     visitor.postorder(v, t);
Chris@16:   }
Chris@16: 
Chris@16:   struct null_tree_visitor {
Chris@16:     template <typename Node, typename Tree> void preorder(Node, Tree&) { }
Chris@16:     template <typename Node, typename Tree> void inorder(Node, Tree&) { }
Chris@16:     template <typename Node, typename Tree> void postorder(Node, Tree&) { }
Chris@16:   };
Chris@16: 
Chris@16: } /* namespace boost */
Chris@16: 
Chris@16: #endif /* BOOST_TREE_STRUCTURE_HPP */