xcode 6 beta 4 - MessageComposeResult is not convertible to OptionalNilComparisonType

Question

I have just upgraded from Xcode 6 Beta 3 to Beta 4. In 3 my app was compiling perfectly however in 4 I have the following error. Can anyone explain and provide a solution pl

Answer 1

func messageComposeViewController(controller: MFMessageComposeViewController!, didFinishWithResult result: MessageComposeResult) {

    switch result.value {

    case MessageComposeResultSent.value :
        println("enviado")

    case MessageComposeResultCancelled.value :
        println("cancelado")

    case MessageComposeResultFailed.value :
        println("fallo")

    default:
        println("")

    }

}