Would it be much easier to implement the boost graph lib if C++ containers could reference themselves? I mean if something like std::list_traits<T> was available so that the iterator class could be got without instantiating the actual list. Simplistically, some thing like... struct vertex; struct edge; typedef std::list_traits<vertex>::iterator Vit; typedef std::list_traits<edge>::iterator Eit; struct edge { Vit source; Vit target; }; struct vertex { std::list<Eit> edges; }; I'm asking because container traits seem to be useful in the work I do, so I'm trying to garner support for them. Thanks, Louis.