Anyone who has programmed with Objective-C (or Swift) for years knows Apple's language deprecation cycle. Write code one year, the next year you are flagged with a deprecation warning -- Xcode of course will help you upgrade your code. Your unchanged code will probably work for another year and then suddenly it is an error. The "magic wand" of Xcode / Clang helps you thru this transistion. Apple likes to break eggs.