Re: A question of style: Returning 'pairs'

FROM : Andy Lee
DATE : Wed Jul 02 21:22:28 2008

On Jul 2, 2008, at 2:48 PM, James Montgomerie wrote:
> 2) Define a custom C struct (like NSRect, but with e.g. 'string' and 
> 'offset' members) and return objects in it.  Just like any other 
> returned objects, the caller would be expected to retain them 
> individually if it needed to keep them around.


Someone asked a similar question recently, with something like this 
struct solution as one of the possible options.  I rejected this 
option, but upon reflection my reasons didn't quite make sense; I 
don't think it's such a bad option now, though it makes me 
uncomfortable for some reason.

Another option you didn't mention is to return *both* values in 
pointers, and have the return type be void.  This way you wouldn't be 
implying one is more important than the other.  A method like this 
should have a name beginning with "get", as in getString:(NSString 
**)stringPtr offset:(int *)offsetPtr.  There is quite a bit of 
precedent for methods of this form -- in the Xcode documentation 
window, you can do an API "Starts With" search, sort by language, and 
look at the Objective-C methods.

--Andy