[boost] boost::result_of

I can't seem to get the result_of template to function, I've tried: #include <boost/utility/result_of.hpp> typedef boost::result_of<F>::type t; with F= int (double) int (*)(double) int (&)(double) std::unary_function<double,int> and all give a long list of errors. I believe that all of these should be OK? So am I doing something obvious wrong (I'm using VC7.1 BTW in case that makes a difference)? Thanks, John.