with errors.swift

func doSomethingTake2(inout error: Error) -> String? {
    let success = (arc4random_uniform(2) == 1) // flip a coin
    if success {return "success"} // succeed
    error = Error.Unlucky
    return nil // fail
}

func doClient1Take2(inout error: Error) -> String? {
    if let string = doSomethingTake2(&error) {
        // blah blah other work
        return string
    } else {
        return nil
    }
}

func doClient2Take2(inout error: Error) -> String? {
    if let string = doClient1Take2(&error) {
        // blah blah other work
        return string
    } else {
        return nil
    }
}

func doConsumerTake2() {
    var error = Error.NoError // have to add default condition here
    if let result = doClient2Take2(&error) {
        // use result here
        print("String: \(result)")
    } else {
        print("Error in doClient2Take2: \(error)")
    }
}