[Boost-users] Quick newbie question

Hello all, I'm just getting started with the boost graph library (and templates) and there are a few details that I can't figure out. -For the life of me I can't find a definition or a typedef for the UniformCostVisitor declared in dijkstra_shortest_paths_.hpp. I've grep'd all the boost header files and looked in the docs, to no avail. -I am writing my own algorithm o use with BFS to find a vertex weighted MST and some other goodies, so i want to implement something very similar to the implementation of dijkstra's. Is it neccessary to define the "VisitorConcept" struct, or do you only need to do this when you (as in me) are going to invoke some concept checking? I think that's it for now...Thanks in advance! Cheers, Jason