It won't. If the compiler attempted to inline, it'd break runtime method replacement and all sorts of other stuff. One problem with this approach is that using

It won't. If the compiler attempted to inline, it'd break runtime method replacement and all sorts of other stuff. One problem with this approach is that using protocols to emulate C++/Java generic syntax will cause name collisions if a class already has the same name as a protocol. NSArray<NSObject> won't work for example, because NSObject is already a protocol.