Thomas Costa wrote:
Will a future version of BGL have a "TerminatorFunc" in all the visitor types?
Throwing an exception as part of the "normal" flow of an algorithm seems to go against most people's C++ philosophy.
There are two points to note. 1. As Peter Dimov said (IIRC), exceptions are just non-local goto. In this case, non-local goto is fine. 2. TerminatorFunc does not do what you're asking for. It does not terminate the search as soon as you find a certain vertces -- for that exception is fine. The TerminatorFunc parameter prevents the search to go *past* certain vertices. Consider: A ------- B -------- C ----------- D \ \ \ E ------ F -------- G If terminator func returns true on 'B', then depth_first_visit will visit 'A', 'B', 'E', 'F', and 'G', but not 'C' or 'D'. It was invented (by me) exactly for that purpose. I wanted to find all paths starting at a given vertex ending is a special 'terminating' vertices. Lastly, I don't think adding this parameter to depth_first_*search* (as Doug suggested), I doubt it's needed. DFS will visit all vertices, and if you want to find a vertex satisfying a predicate you can use the 'find_if' algorithm ;-) - Volodya