Added thirdparty: boost library

thirdparty/include/boost/graph/tree_traits.hpp

@@ -0,0 +1,48 @@
+//  (C) Copyright Jeremy Siek 1999.
+// 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)
+
+#ifndef BOOST_TREE_STRUCTURE_HPP
+#define BOOST_TREE_STRUCTURE_HPP
+
+#include <boost/tuple/tuple.hpp> //For boost::tie()
+
+namespace boost
+{
+
+template < class T > struct tree_traits
+{
+    typedef typename T::node_descriptor node_descriptor;
+    typedef typename T::children_iterator children_iterator;
+};
+
+template < class Tree, class TreeVisitor >
+void traverse_tree(typename tree_traits< Tree >::node_descriptor v, Tree& t,
+    TreeVisitor visitor)
+{
+    visitor.preorder(v, t);
+    typename tree_traits< Tree >::children_iterator i, end;
+    boost::tie(i, end) = children(v, t);
+    if (i != end)
+    {
+        traverse_tree(*i++, t, visitor);
+        visitor.inorder(v, t);
+        while (i != end)
+            traverse_tree(*i++, t, visitor);
+    }
+    else
+        visitor.inorder(v, t);
+    visitor.postorder(v, t);
+}
+
+struct null_tree_visitor
+{
+    template < typename Node, typename Tree > void preorder(Node, Tree&) {}
+    template < typename Node, typename Tree > void inorder(Node, Tree&) {}
+    template < typename Node, typename Tree > void postorder(Node, Tree&) {}
+};
+
+} /* namespace boost */
+
+#endif /* BOOST_TREE_STRUCTURE_HPP */