ios – xcode 6 beta 4 – MessageComposeResult不能转换为OptionalNilComparisonType

func messageComposeViewController(sendMsg: MFMessageComposeViewController, didFinishWithResult result: MessageComposeResult) {

    switch result {

    case MessageComposeResultSent :    //Error: MessageComposeResult is not convertible to _OptionalNilComparisonType
        label2.text = "Msg Sent"

    case MessageComposeResultCancelled : //Error: MessageComposeResult is not convertible to _OptionalNilComparisonType
        label2.text = "Msg Send Cancelled"

    case MessageComposeResultFailed :   //Error: MessageComposeResult is not convertible to _OptionalNilComparisonType
        label2.text = "Msg Send Failed"

    default:
        label2.text = "Msg Error"

    }

    self.dismissViewControllerAnimated(true, completion: nil)
    self.reloadInputViews()

}

这是该模块与Swift桥接的方式中的一个错误.报告.要使用该模块,请保持Objective-C直到修复Swift桥接错误.

在我看来,bug的主要部分似乎是：

>这应该是一个枚举,而不是;这是一个结构

> struct有一个值,它应该能够进行比较,但它没有getter(你可以在初始化时设置它但你以后不能得到它)