How to Emulate Double Dispatch in Objective-C

Question

I'm, trying to emulate a Double Dispatch in Objective-C.

I know Objective-C does not support function/method overloading. But can you emulate this?

Any idea.

https://stackoverflow.com/questions/19882396/double-dispatch-for-collision-handling-with-spritekit — matt, May 28 '18 at 19:28

score 1 · Answer 1 · answered May 28 '18 at 19:31

1

You can do it as in C++/C# with 2 single dispatches (aka "visitor" pattern, see https://en.wikipedia.org/wiki/Double_dispatch#Double_dispatch_in_C++ ).

Or you can do it manually with some runtime type checking on the argument (see isMemberOfClass).

answered May 28 '18 at 19:31

battlmonstr

Do you have any simple example of Visitor pattern? – Josué H. May 28 '18 at 22:23
https://stackoverflow.com/questions/9366079/visitor-pattern-in-objective-c – battlmonstr May 29 '18 at 10:43

score 0 · Accepted Answer · answered Jun 15 '18 at 15:14

0

In this repo give an example of how to Implement Double Dispatch in Objective-C

answered Jun 15 '18 at 15:14

Josué H.

1

This is a link only answer. It would nice that you give a summary of how it works, so that the readers don't have to go all the files in the repo to find out. – Christophe Sep 30 '18 at 22:02

2 Answers2