Knowing whether a class inherits from another class

[Aurelien]

I think the message subject is fairly explicit...

Note that I already know how to check wether an *object* is of a class 
that inherits from a given class (i.e. with the isKindOf method). No, I 
want to have the information directly for the Class.

BTW: is there any documentation about Class ?

BTW 2: I'm always sending cString messages to NSStrings when I have to 
format them (e.g. in an NSLog, with the %s placeholder); is there a more 
convenient way to do this ?

Thanks in advance,

Aurélien