[boost] [BGL] How to stopping prematurely a graph exploration

Hi to all, I'm searching for a good method to stopping prematurely a graph exploration, e.g. when I've just founded and explored a particular vertex. I think I've to create a visitor to which passing the particular vertex, but I don't know how to configure it. A very brutal method is to wrap the exploration function in a try-catch block, and then throw an exception in the examine_vertex funtion. I want to believe that there's a more elegant method than this... Best regards, Cosimo Calabrese.