I'd like to do shortest path on an implicit graph - i.e. building it as I go, on examining a vertex I'd like to add the adjacent edges before continuing. Is this supported? If so, can someone point me in the right direction? If not, how could I do this in boost? The boost astar algorithm claims to support implicit graphs using a modified version of the boost bfs algorithm (nonconst_bfs.hpp). This modified version didn't exist in my distribution so I followed the comments in a document from the authors (link below) and removed the const requirements for the graph in breadth_first_search.hpp. The example (implicit example from pdf below, pg 12) compiles ok but seg faults when trying to add a vertex (vertex_t v = add_vertex(vert_prop(white_color), g); page 16 of pdf) in the visitor (some adds succeed first). Any ideas? http://www.cs.rpi.edu/~beevek/research/astar_bgl04.pdf thanks Ian