How @nonbjc could help with circularity?

Using Swift
1

Hello!

I found in the docs that:

You use the nonobjc attribute to resolve circularity for bridging methods in a class marked with the objc attribute

could help to resolve circularity. here

Could somebody help with an example of it?

Also nonobjc method could override objc method from here

Example:

public class P: NSObject {
    @objc func test() {}
}

public class T: P {
    @nonobjc override func test() {}
}

Thanks

2

Could somebody help me with it please? Thank you!

3

You can't override an @objc method with a @nonobjc one. It's written in the documentation you linked to:

A method marked with the nonobjc attribute can’t override a method marked with the objc attribute.

You can do the reverse however (override a @nonobjc method with an @objc one). So this works:

public class P: NSObject {
    @nonobjc func test() {}
}

public class T: P {
    @objc override func test() {}
}

I'm not sure what kind of problem you're trying to solve here though.

Note that @nonobjc is rarely needed since Swift 3 made it the default when it's not needed for an override or a protocol conformance.

1 Like
4

There is a code snippet that shows that it's possible:

public class P: NSObject {
    @objc func test() {}
}

public class T: P {
    @nonobjc override func test() {}
}

Also I was checked the documentation for @nonobjc attribute and there was a statement for circular dependency that I didn't get.

5

You could file a bug report. The documentation says it's not possible. Either the compiler has a bug or the documentation is wrong.

I'm not sure either what is the meaning of "circularity" in this context.

1 Like
6

Will do it, just need to confirm with other people that it's incorrect.

"Circularity" is other topic, it doesn't relate to override. Here I still need some answer.

Thank you

7

Is anybody could suggest me about this two topics? Thanks!