问题
I tried googling but i was unable to locate the Apples Documentation where they say that ARC - automatic reference counting supports for iOS 4.3. Can someone tell me if this is true ? if so can you post me a link to apples documentation where it says so.
回答1:
Transitioning to ARC:
ARC is supported in Xcode 4.2 for Mac OS X v10.6 and v10.7 (64-bit applications) and for iOS 4 and iOS 5. Weak references are not supported in Mac OS X v10.6 and iOS 4.
回答2:
Though ARC is in the new features list of iOS 5, apparently it is enabled by the compiler and that capability became 'switched on' for iOS 4 at the same time the updated compiler for iOS 5 was released.
I was provided this general clarification from Apple DTS. Cheers,
来源：https://stackoverflow.com/questions/8771791/does-ios-4-3-support-arc