What's the compatibility of ARC and Storyboard considering devices and iOS?
Will ARC and Storyboard work on iPhone 3G, 3GS, 4 and 4S?
Will ARC and Storyboard work on iOS 4 and 5?
Phlibbo
ARC runs with 5.0 or higher, Storyboard also needs iOS 5. Therefore, both are potentially available with the iPhone 3GS and above.
EDIT: Obviously, ARC is also compatible with iOS 4.0 and above, once you don't use weak. I briefly tested it, seems to work. That would mean that the iPhone 3G would also be compatible.
来源：https://stackoverflow.com/questions/7815128/compatibility-of-arc-and-storyboard