I'm trying to build a library where the user provides a list of functions objects (or plain functions) and I need to extract the argument information from the types of these functions. Am I correct in believing that there is no generic way to do that with function objects? It will be easy to extract the signature from the boost::function objects, but I can't figure out how to extract argument information from function objects created by boost::bind. Is it possible? I guess it wouldn't be too hard to fall back on the old STL style typedefs (first_argument_type, second_argument_type) when possible and require the user to wrap functions with more parameters in a boost::function object otherwise. Would it be desirable to make the proposed function_types library work on function objects whose argument information can be queried, like the result_of template does for return types? Thanks, Brock