ios - Swift: Conforming to protocols using default values

Question

Is there a way to conform to a Swift protocol using default values?

The following example results in a Type 'FunExample' does not conform to protocol 'Example':

protocol Example {
    func doSomething(with: String)
}

class FunExample: Example {
    func doSomething(with: String, butMakeItFun: Bool = true) {
        // implementation
    }
}

...even though I actually implicitly conform since this is identical to:

protocol Example {
    func doSomething(with: String)
}

class FunExample: Example {
    func doSomething(with: String) {
        self.doSomething(with: with, butMakeItFun: true)
    }
    func doSomething(with: String, butMakeItFun: Bool) {
        // implementation
    }
}

Is there a cleaner way to provide conformance using default values? Or am I missing something conceptually when I say that the first example should also pass conformance?

To clarify: I understand why the error is produced. My question is more conceptual (whether Swift should work this way) and whether there is an elegant way around it.

Answer 1

You can go with extension for the more cleaner way! Make an extension with the same protocol methods and pass the default values which you want. Let's say:

protocol Example { //Main Protocol
    func doSomething(with: String, butMakeItFun: Bool)
}

extension Example { //Make to pass the default values if you want
    func doSomething(with: String, butMakeItFun: Bool = false) {
        return doSomething(with: with, butMakeItFun: butMakeItFun)
    }
}

class FunExample: Example { //Protocol Acceptance
    func doSomething(with: String, butMakeItFun: Bool) {
        debugPrint("(with)")
        debugPrint(butMakeItFun)
    }
}

You can call it via following ways:

1. FunExample().doSomething(with: "Hello Default Values...")
2. FunExample().doSomething(with: "..........", butMakeItFun: true)

Update

So based on your comment, here is what I have came up! You can take a variable under the protocol which surely says true or false as a default implementation and later-on you can change it in your class.

protocol Example {
    var isFun: Bool {set get}
    func doSomething(with: String)
}

class FunExample: Example {

    //var isFun: Bool = false - In case you want to change value

    func doSomething(with: String) {
        doSomething(with: with, butMakeItFun: isFun)
    }

    func doSomething(with: String, butMakeItFun: Bool) {
        debugPrint(with)
        debugPrint(butMakeItFun)
    }
}

extension Example {
    var isFun: Bool {
        get { return true /* Your Default Value */ } set {}
    }
}