Calling protocol default implementation from regular method

Question

I\'m wondering if it\'s possible to achieve such a thing.
I have a Playground like this:

protocol Foo {
    func testPrint()
}

extension Foo {
    func          


        

Answer 1

In case your protocol has associatedType or Self requirements, then the cast will not work. To work around this, create a "shadow" default implementation that both the regular default implementation and the conforming type can call.

protocol Foo { 
    associatedType Bar
}

extension Foo {
    func testPrint() {
        defaultTestPrint()
    }
}

fileprivate extension Foo { // keep this as private as possible
    func defaultTestPrint() {
        // default implementation
    }
}

struct Bar: Foo {
    func testPrint() {
        // specialized implementation
        defaultTestPrint()
    }
}