Fastest way to get array of NSRange objects for all uppercase letters in an NSString?

Question

I need NSRange objects for the position of each uppercase letter in a given NSString for input into a method for a custom attributed string class. 

There are of course q

Answer 1

a function such as isupper* in conjunction with -[NSString characterAtIndex:] will be plenty fast.

*isupper is an example - it may or may not be appropriate for your input.