1.1 --- a/lemon/bits/graph_extender.h	Tue Feb 12 21:08:29 2008 +0000
     1.2 +++ b/lemon/bits/graph_extender.h	Thu Feb 28 16:41:56 2008 +0100
     1.3 @@ -20,6 +20,7 @@
     1.4  #define LEMON_BITS_GRAPH_EXTENDER_H
     1.5  
     1.6  #include <lemon/bits/invalid.h>
     1.7 +#include <lemon/bits/utility.h>
     1.8  
     1.9  #include <lemon/bits/map_extender.h>
    1.10  #include <lemon/bits/default_map.h>
    1.11 @@ -333,6 +334,8 @@
    1.12      typedef Base Parent;
    1.13      typedef GraphExtender Digraph;
    1.14  
    1.15 +    typedef True UndirectedTag;
    1.16 +
    1.17      typedef typename Parent::Node Node;
    1.18      typedef typename Parent::Arc Arc;
    1.19      typedef typename Parent::Edge Edge;