Possible Duplicate:
How does the new automatic reference counting mechanism work?
Can someone explain succinctly how automatic Reference Counting in Objective C works?
Possible Duplicate:
How does the new automatic reference counting mechanism work?
Can someone explain succinctly how automatic Reference Counting in Objective C works?
It's not a quick "type it up for the internet" answer. There was a nice hour-long lecture about it at WWDC 2011 that was dense with information.
Suffice it to say that the next step in compiler technology and code analysis is at the heart of how it works.