Hello list members, I'm evaluating the bgl library of boost for a while. Now I'm interessted in the question how to use bgl for managing a n-tree data structure. Is there a graph which checks if an existing vertex has an in-edge and prevents adding a second one? With kind regards, Manuel Siebeneicher -- Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer