Supressing warning for a class (trying to simulate an Abstract class in objc)

Question

Hi all!

This is the situation. I've been a C++ programmer for ages. I like abstract classes and "interfaces" so I would likt to do the same using objc.

I use a protocol for my interfaces, but the problem is that when my abstract class inherits from the protocol (I don't want to implement it here) I get warnings like:

warning: method definition for 'XXXXX' not found and 'XXXXX' class does not fully implement the 'XXXXXX' protocol.

Is there anyway to supress this? I hope child classes of this ones will throw "correct warnings" if base class did not implemented the protocol.

Another option is to inherit from the protocol just when needed, but I like to force this in the base class to make sure inherited implementes the interface.

Any tip?, Thanks in advance.

Answer 1

I don't think there is a solution in a way you are looking for. You must define all methods declared in the protocol, at least implement them as an empty methods.

I understand that you are looking for a C++ like code, but Obj-C is different and we must live with it. Also, gcc supports c++/obj-c mix, so you can write some part of the project in pure C++ what is great when you need some low-level code or want something easy to port.

Answer 2

When you implement a protocol in an Objective-C class, you have to implement all the methods. However, you can provide stub implementations. This mailing list post describes how to use doesNotRecognizeSelector: in "abstract" classes.