问题 The question started here, but after all the updates it is already a different question with a different title. My Graph type is defined as follows: using Graph = boost::adjacency_list<vecS, setS, undirectedS, State, CostType>; where CostType happens to be int . I am trying to obtain the Kamada-Kawai spring layout as follows: template <class PointMap> PointMap layout() const { PointMap res; boost::associative_property_map<PointMap> temp(res); circle_graph_layout(g_, temp, 10.0); // https:/