ceph/src/boost/libs/graph/include/boost/graph/tree_traits.hpp

   1 //  (C) Copyright Jeremy Siek 1999.
   2 // Distributed under the Boost Software License, Version 1.0. (See
   3 // accompanying file LICENSE_1_0.txt or copy at
   4 // http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef BOOST_TREE_STRUCTURE_HPP
   7 #define BOOST_TREE_STRUCTURE_HPP
   8
   9 #include <boost/tuple/tuple.hpp> //For boost::tie()
  10
  11 namespace boost {
  12
  13   template <class T>
  14   struct tree_traits {
  15     typedef typename T::node_descriptor node_descriptor;
  16     typedef typename T::children_iterator children_iterator;
  17   };
  18
  19
  20   template <class Tree, class TreeVisitor>
  21   void traverse_tree(typename tree_traits<Tree>::node_descriptor v,
  22                      Tree& t, TreeVisitor visitor)
  23   {
  24     visitor.preorder(v, t);
  25     typename tree_traits<Tree>::children_iterator i, end;
  26     boost::tie(i, end) = children(v, t);
  27     if (i != end) {
  28       traverse_tree(*i++, t, visitor);
  29       visitor.inorder(v, t);
  30       while (i != end)
  31         traverse_tree(*i++, t, visitor);
  32     } else
  33       visitor.inorder(v, t);
  34     visitor.postorder(v, t);
  35   }
  36
  37   struct null_tree_visitor {
  38     template <typename Node, typename Tree> void preorder(Node, Tree&) { }
  39     template <typename Node, typename Tree> void inorder(Node, Tree&) { }
  40     template <typename Node, typename Tree> void postorder(Node, Tree&) { }
  41   };
  42
  43 } /* namespace boost */
  44
  45 #endif /* BOOST_TREE_STRUCTURE_HPP */