[Boost-users] [BGL] Iterate through neighbour vertices

Hi, I have a directed graph (vecS, vecS, bidirectionalS) and I'm trying to iterate through the neighbour vertices of a vertex u. When using for (tie(ai0,ai0_end) = adjacent_vertices(u,g); ai0 != ai0_end; ++ai0) the code goes only through the out vertices of u. Is there a way to iterate through all the neighbouring vertices in one loop (i.e. through both the out and in vertices of u)? Thanks, Rui