Hello, I cannot compile the boost/graph library 1.32.0 on a SUN machine using Sun C++ 5.5. I get the following error message : boost_1_32_0/boost/graph/depth_first_search.hpp", line 377: Error: Default arguments cannot be added in later declarations of the template function in the same scope. which does make sense since the compiler cannot decide which routine depth_first_visit to use if the second routine (line 371) has an extra template but the the extra template has a default value. So in boost/graph/depth_first_search.hpp, I simply deleted the default argument : template <class IncidenceGraph, class DFSVisitor, class ColorMap, class TerminatorFunc> void depth_first_visit (const IncidenceGraph& g, typename graph_traits<IncidenceGraph>::vertex_descriptor u, DFSVisitor vis, ColorMap color, TerminatorFunc func = TerminatorFunc()) becomes template <class IncidenceGraph, class DFSVisitor, class ColorMap, class TerminatorFunc> void depth_first_visit (const IncidenceGraph& g, typename graph_traits<IncidenceGraph>::vertex_descriptor u, DFSVisitor vis, ColorMap color, TerminatorFunc func) Unfortunately the compilation was afterwards not successful; this time I got "boost_1_32_0/boost/graph/named_function_params.hpp", line 500: Error: Cannot return const boost::bgl_named_params<boost::detail::components_recorder<int*>, boost::graph_visitor_t, boost::no_property> from a function that should return boost::detail::error_property_not_found. "boost_1_32_0/boost/graph/depth_first_search.hpp", line 354: Where: While instantiating "boost::get_param<boost::graph_visitor_t, boost::root_vertex_t, boost::detail::components_recorder<int*>, boost::no_property>(const boost::bgl_named_params<boost::detail::components_recorder<int*>, boost::graph_visitor_t, boost::no_property>&, boost::root_vertex_t)". "boost_1_32_0/boost/graph/depth_first_search.hpp", line 354: Where: Instantiated from non-template code. "boost_1_32_0/boost/graph/depth_first_search.hpp", line 355: Error: Could not find a match for boost::vertices<boost::T>(const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::no_property, boost::no_property, boost::no_property, boost::listS>). big thanks for any help, Laurent