I’m using Xcode 4.2 (build 4C199) on Snow Leopard(!), which should be the latest version as of this writing. In figure 2.3 there is a checkbox “Use Automatic Reference Counting”, which is checked in the figure, but missing in my version of Xcode. There is, however, a build setting called “Objective-C Automatic Reference Counting” under “Apple LLVM compiler 3.0 - Language”. I wonder if it is enough to just enable it there or wether there are more subtle implications. Moreover, why is the checkbox missing - because I’m on Snow Leopard?
There is indeed at least one implication, the empty project won’t build, because the automatically generated code uses [super dealloc] … is it possible that this issue is related to the “Window-Based Application” announcement for iOS5?