Hi, On Thu, 27 Nov 2003, Ali Tofigh wrote: alix> Is there any guarantee that Vertex descriptors are some kind of integers? In alix> the examples provided add_edge is called with integers as vertex descriptors. alix> Does the choice of parameters for the adjacency_list graph make a difference alix> on this issue? E.g. whether the we choose vecS or listS as VertexList? Yes it makes a difference. When VertexList=vecS the vertex descriptor is int. When VertexList=listS the vertex descriptor is void*. alix> If future flexibility of the program being written is a factor (e.g. alix> if we want it to be easy to change the definition of the graphs alix> without necessarily changing other parts of the code) is it better alix> to use add_vertex, followed by add_edge using the vertex descriptors alix> returned by add_vertex? Yes. Cheers, Jeremy ---------------------------------------------------------------------- Jeremy Siek http://php.indiana.edu/~jsiek/ Ph.D. Student, Indiana Univ. B'ton email: jsiek@osl.iu.edu C++ Booster (http://www.boost.org) office phone: (812) 856-1820 ----------------------------------------------------------------------