Use of nested references in objective C

Question

Getting an error message "Nested functions are disabled, use -fnested" etc in XCode/ObjC.

Here's the code (balls is an NSMutableArray pointing at a bunch of UIViews).

CGPoint pos=[[self.balls objectAtIndex:pointidx] center];

But the following seems to compile ok.

UIView *ref=[self.balls objectAtIndex:pointidx];
CGPoint pos=ref.center;

Should I use "-fnested-functions to re-enable (and if so where do I put the "-fnested-functions")? Or should I just put up with additional step of creating a UIView* pointer first? ty.