Selector Not Recognized

FROM : David Alter
DATE : Tue Jul 11 23:49:54 2006

I have a sub class of an object. The sub class has no additional 
instance variables, just some additional methods. I get a pointer to 
the parent object and I want to call methods available in the sub 
classed objects. So I tried to case it and make the call. To this I 
get "selector not recognized". Is there a way to do this? I can do 
this in C++.

thanks for the help

-dave


Example bellow if needed

@interface myParent : NSObject {
   int somedata
}

- (int) getSomeDataPlusOne; //

@end


In the main body of code
   
   myParent * myObj =  [[myParent alloc] init];

   mySub * mysub = (mySub *) myObj;

   int val = [mysub getSomeDataPlusOne]; // It chokes here with 
"selector not recognized"