I am kind of new to C++ and also BGL, so it'll be great if you can help me with this problem! I'm iterating over all the vertices of my graph, and each time I iterate, I want to *mark* a vertex (which has some specific degree for example, or some other property that I can calculate), so as not to iterate over it the next time. I'll do this process until all vertices are marked, so no more iteration. For now, what I'm doing is putting the marked vertices in a separate list, and each time I iterate over all vertices again and I check whether each vertex is in the marked list (which is very inefficient). Could you please help me with an efficient way of doing this? I was thinking to use Property Map but I have no idea how! Any small piece of code will be appreciated. Thanks a lot!