[Boost-users] Vertex descriptors in adjacancy_list

Is there any guarantee that Vertex descriptors are some kind of integers? In the examples provided add_edge is called with integers as vertex descriptors. Does the choice of parameters for the adjacency_list graph make a difference on this issue? E.g. whether the we choose vecS or listS as VertexList? If future flexibility of the program being written is a factor (e.g. if we want it to be easy to change the definition of the graphs without necessarily changing other parts of the code) is it better to use add_vertex, followed by add_edge using the vertex descriptors returned by add_vertex? Regards, A. T.