Hello, in parallel to trying to get 1_34_1 compiling again, I'll also try to understand why the code won't compile with 1_37_0. Now I found the following program which actually compiles neither with 1_34_1 nor with 1_37_0, but it should: ------------------- #include <utility> #include <vector> #include <boost/graph/adjacency_list.hpp> template <class Graph> inline Graph orthogonality_relation() { typedef std::pair<unsigned int, unsigned int> edge_type; std::vector<edge_type> ev; Graph g(ev.begin(), ev.end(), 0, 0); return g; } typedef boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS> UndirectedGraph; int main () { orthogonality_relation<UndirectedGraph>(); } ------------------- The abbreviated error-message from gcc (version 4.1.2) is: Error.cpp:17: instantiated from here Boost/1_37_0+4.1.2/include/boost-1_37_0/boost/graph/detail/adjacency_list.hpp:2113: error: invalid type argument of ‘unary *’ where line 17 is the last line of the main-function. Oliver