Hi all, I have written a small grammar for command line parsing where function binders could be added as actors (callback) of a distinct option. The simple example below shows that the free function id(...) is called if the option -i is getting parsed and the bound member function is called when -j is given: bool id(int i) { return true; /* if id satisfies some preconditions, the parser will evaluate the result value */ } struct Id { void id(int i) { // the parser will not evaluate the 'void' result value } }; Id ident; bool rc = cmdline::Parser ::parse(argc, argv, cmdline::Option<'i'>().doc("an integer identifier")) >> id <= cmdline::Option<'j'>().doc("another integer")) >> boost:bind(Id::id, &ident, _1) ); The problem now is that I want to deduce the result type of the given actor as well as the argument type. Retrieving the result type is manageable with boost binders but I have no idea how I could retrieve the argument type in order to do a proper conversion from char* to int without the usage of make_adaptable<> which breaks the elegance of the binder usage at this point. My self-written binder class exposes appropriate typedefs so the writer of the parser grammar does not have to cope with all that 'magic' template stuff, but I cannot get a working solution for boost::bind nor do I get a working solution with tr1 binders. Maybe anybody could help or at least could explain me why the boost classes do not define these simple typedefs? Regards, Martin