How to pass a Swift structure as a parameter to an Objective-C method

Question

I have an Objective-C method that takes a type parameter id, and I want to pass a Swift structure to it.

ObjcClass.m file:

@implementation ObjcClass
+ (void)addListener:(id)listener {
    // Do something with listener
}

DemoStruct.swift file:

struct DemoStruct {
    func registerAsListener() {
        ObjcClass.addListener(self) // Can't find a way to do this
    }
}

The compilation error message I get:

The type "DemoStruct" does not comply with the protocol "AnyObject"

So my question is: how to make an Objective-C accept method Anyinstead AnyObjectand is there such a thing?

Answer 1

The best I have found is to wrap the Box class

public class Box<T> {
    let unbox: T
    init(_ value: T) {
        self.unbox = value
    } }

Answer 2

You cannot do this.

Swift lines are not available from Objective-C. This is stated in Apple’s book Using Swift With Cocoa and Objective-C:

- , @objc, Objective-C. Swift, :

• , Swift
• , Swift
• , Swift
• , Swift
• , Swift
• Swift

: Apple Inc. " Swift Cocoa Objective-C." . https://itun.es/gb/1u3-0.l