[Boost-users] [graph] Convert bidirectional graphs into directed graphs

Hello, I need to convert any bidirectional graph into an adjacency_list<vecS,vecS,directedS>, but looks like the copy constructor cannot handle it (needs the same type in input). I don't see any simple way to convert any directed graph into an adjacency_list<vecS,vecS,directedS>. Is there any more-or-less-simple way to do it that I don't know? May be there is a way to copy graphs constrained not by the concrete type of the graph, but only, may be, on graph concepts? Thanks, Juan