[boost] [1.36.0: Graph] unused variable warning in topological_sort.hpp

in boost/graph/topological_sort.hpp, line 40 is an unused variable (u): template <typename Edge, typename Graph> void back_edge(const Edge& u, Graph&) { throw not_a_dag(); } Would be great if that could be fixed for the next release. Keep up the great job! Best regards Christoph