Hi, i tried to build a property map using the associative_property_map and putting a poiter to a pure virtual class as value type but i had some error i can't understand. I also tried with a normal class pointer and i had the same problem. /usr/include/boost/dynamic_property_map.hpp:202: error: no match for ‘operator<<’ in' out << boost::get ... I'm new to boost and c++, it's likely that i've done some stupid errors. I hope somebody can help me. That's a test that reproduce the problem: f#include <boost/graph/adjacency_list.hpp> #include <boost/dynamic_property_map.hpp> #include <boost/property_map.hpp> #include <map> #include <iostream> typedef boost::adjacency_list<boost::vecS,boost::vecS,boost::undirectedS>Graph; typedef boost::graph_traits<Graph>::vertex_descriptor vertex_descriptor; class Interface { virtual void test()=0; }; class Implement : Interface { void test(){std::cout << "ok" <<std::endl;} }; int main() { std::map<vertex_descriptor,Interface&>* testmap = new std::map<vertex_descriptor, Interface&>; boost::associative_property_map<std::map<vertex_descriptor,Interface&>

test_map(*testmap); boost::dynamic_properties dp; dp.property("test", test_map); //that's the line that cause the problem Implement i; put("test", dp, 0, i); }