Hi Chris, On Wed, 2 Oct 2002, Chris Russell wrote: [snip] cdr> finish_vertex method in a dfs_visitor will not compile however. This cdr> is because the graph is passed by const reference into the visitor cdr> method and in_edges requires a non-const graph reference? No, in_edges is declared const for the graph parameter, at least for adjacency_list, and it should be for other graph types as well. cdr> Generally, I would like to be able to daisy chain graph algorithms - cdr> that is invoke a sub-algorithm from within a visitor method called by cdr> a controlling algorithm. This would require that the sub-algorithm cdr> not change the graph topology, trample on properties used by its cdr> controller (e.g. coloring), or otherwise invalidate vertex cdr> descriptors or iterators so some care would need to be taken in cdr> designing the sub-algorithm. But it seems like a useful mechanism for cdr> extension. You can do that as long as you use a different color map, etc. Regards, Jeremy ---------------------------------------------------------------------- Jeremy Siek http://php.indiana.edu/~jsiek/ Ph.D. Student, Indiana Univ. B'ton email: jsiek@osl.iu.edu C++ Booster (http://www.boost.org) office phone: (812) 855-3608 ----------------------------------------------------------------------