Apple changed their Memory Management Rule for Naming Convention

Question

As stated in Cocoa Memory Management Rules from before

You take ownership of an object if you create it using a method whose name begins with “alloc” or “new” or contains “copy” (for example, alloc, newObject, or mutableCopy), or if you send it a retain message.

haven't read it after December 2010, but since has changed since then to

You “create” an object using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy” (for example, alloc, newObject, or mutableCopy).

Notice that now, it is required to have "copy" as a prefix. This resulted to a few memory related warnings from Clang Static Analyzer :(. After searching the interwebs, I haven't got to a conclusion as to why was this changed since this is one of the base foundations of Memory Management for iOS.

Does anybody know why? Thanks!

Answer 1

There were some methods that contained "Copy" in their text, but were clearly not copying methods. For example, +[NSData dataWithBytesNoCopy:length:]. It was, of course, possible to use annotations for the static analyzer to inform about the nonstandard behavior, but in general I suspect that almost nobody (yourself excepted) ever wrote a copy method that didn't start with copy or mutableCopy, so they decided to just simplify things.

I'm glad they did, frankly, as I've run into the opposite problem, where a method contained the word "Copy" but was not intended to return an owning reference.