Gist for reddit

protocol MyProtocol {
    func doSomething() -> String
    
    // factory
    static func make() -> MyProtocol
}

typealias WidgetFactory = () -> MyProtocol

class WidgetA: MyProtocol {
    func doSomething() -> String {
        return "Doing the Widget A stuff"
    }
    
    // Factory
    static func make() -> MyProtocol {
        return WidgetA()
    }
}

class WidgetB: MyProtocol {
    func doSomething() -> String {
        return "Doing the Widget B stuff"
    }
    
    // Factory
    static func make() -> MyProtocol {
        return WidgetB()
    }
}

enum WidgetType {
    case typeA, typeB
}

enum WidgetHelper {
    static func factory(for type: WidgetType) -> WidgetFactory {
        switch type {
        case .typeA:
            return WidgetA.make
        case .typeB:
            return WidgetB.make
        }
    }
}

var factory = WidgetHelper.factory(for: .typeA)
var myWidget = factory()
myWidget.doSomething() // Widget does the Widget A stuff

factory = WidgetHelper.factory(for: .typeB)
myWidget = factory()
myWidget.doSomething() // Widget does the Widget B stuff