ARC is function of the compiler rather than the device, so technically it has nothing to do with the OS it is being used on. The difference between the two is the actual zeroing of weak references. Read this for even more info about it.
Running an application that was compiled with ARC on a device with an OS prior to 5.0 will essentially manually zero out references rather than actually zero them out. The automatic zeroing is a core feature of ARC and is why you no longer need to call dealloc or release objects.
ARC is a compiler level feature. So it should work if you are able to compile your code with the latest LLVM 3 compiler. Some very old code bases (mostly old C language third party libraries) that require GCC compiler will not work (such code bases are very very rare)
Zero-ing weak references, a run time feature that ARC takes advantage of, is not available on OSes before iOS 5/Lion. But ARC without weak references will still work.
I want to setup my local development machine so that any requests for *.local are redirected to localhost . The idea is that as I develop multiple sites, I can just add vhosts to Apache called site1.local , site2.local etc, and have them all resolve to localhost , while Apache serves a different site accordingly.
ARC is function of the compiler rather than the device, so technically it has nothing to do with the OS it is being used on. The difference between the two is the actual zeroing of weak references. Read this for even more info about it.
ReplyDeleteRunning an application that was compiled with ARC on a device with an OS prior to 5.0 will essentially manually zero out references rather than actually zero them out. The automatic zeroing is a core feature of ARC and is why you no longer need to call dealloc or release objects.
Don't know where you saw the bit about 4.3 (do you have a link?) - but in the "Transitioning to ARC Release Notes" Apple says iOS 4.
ReplyDeleteARC is a compiler level feature. So it should work if you are able to compile your code with the latest LLVM 3 compiler. Some very old code bases (mostly old C language third party libraries) that require GCC compiler will not work (such code bases are very very rare)
ReplyDeleteZero-ing weak references, a run time feature that ARC takes advantage of, is not available on OSes before iOS 5/Lion. But ARC without weak references will still work.