🚀 go-pugleaf

In article <pauld.767898877@sarge> pauld@verdix.com (Paul Durbin) writes:

>I attempt to use a member function as callback but all three arguments (to the
>callback) are garbage. If I make it a friend then the arguments are correct,
>but then I can't get to the class data, without reference thru an instance of
>the class and I don't want the data to be static.

>So, what is causing this problem? Could I possibly use the *this pointer as
>the client_data to the callback, then cast to the appropriate class?

Not that one can tell from your post, but I'm assuming you mean Windows 
callbacks functions, as used by EnumChildWindows or something?

Of course normal member functions cannot be used for this purpose, having the 
hidden this pointer in the parameter list: only static member functions (or 
plain old functions) can be used as Windows callbacks.

To get to instance data, you can certainly pass 'this' and cast it; you could 
also assign 'this' to a static pointer to type <class>.

Cheers,

Kit Kauffmann   kitk@mudshark.sunquest.com (Internet)
                73363,447 (Compu$erve)
                (801) 277-5790