Question

I know NSDictionary can be used to return multiple things from a method when all the objects are Objective C type objects, but is there a way to package objects that are non-Objective C?

I have a method that I need to return an int and an IplImage. Without converting the IplImage to a NSValue (which I do not know how to do and wish to avoid), can I return 2 items from a method?

Also note that this method is defined in a separate class from which it is being called, thus I don’t think I can use a class variable to store the int (or maybe I can?).

Thanks.

Answer 1

this approach will work for simple cases, i am sure you have seen it:

- (BOOL)caclulate:(NSError**)outError;

it returns a BOOL and an NSError.

To return an int:

- (BOOL)caclulate:(int*)outInt;

Using that approach, you can declare your method like this:

- (int)calculate:(IplImage*)outImage;

and then the caller’s code takes the following form:

IplImage outImage;
int result = [object calculate:&outImage];