Hi David, Please take a closer look at: http://boost-consulting.com/boost/libs/parameter/doc/html/index.html#id15 [quote] template <class T> struct construct2 { typedef T result_type; template <class A1, class A2> T operator() { return T(a1,a2); } }; and use Boost.Bind_ to generate the function object:: boost::bind(construct2<default_color_map>,num_vertices(g),i) [/quote] That won't compile, and library called Boost.Bind (not Bind_) :). That should be: template <class T> struct construct2 { typedef T result_type; template <class A1, class A2> T operator(A1 & a1, A2 & a2) { return T(a1,a2); } }; and use Boost.Bind to generate the function object:: boost::bind(construct2<default_color_map>(),num_vertices(g),i) isn't it? -- Pavel Chikulaev