[Boost-users] [graph] internal predecessor map

Can I store an edge_descriptor of a predecessor edge as an internal/bundled property? I am currently doing this: struct EdgeProperties; struct VertexProperties { double x; double y; double weight; int dist; boost::graph_traits< boost::adjacency_list >::edge_descriptor pred; int app_height; bool mark; }; struct EdgeProperties { double length; }; int main() { using namespace boost; typedef adjacency_list Graph; } This is legal, isn't need? Obviously the definition of EdgeProperties is not needed where it is first used. But is this the proper way to do it, or is there a more elegant way?