在 Swift 3 中获取 GCD 标签

我有一些代码可以获取当前 GCD 队列的标签以用于日志记录，在 Swift 2 中如下所示：

if let queueName
    = String(UTF8String: dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL)) where !queueName.isEmpty {
    detailedMessage += "[" + queueName + "] "
}

Xcode 8 将其转换为 Swift 3 后，它看起来像这样：

if let queueName
    = String(validatingUTF8: DISPATCH_CURRENT_QUEUE_LABEL.label), !queueName.IsEmpty {
    detailedMessage += "[" + queueName + "] "
}

然而，当我构建时，Xcode 给了我以下错误：

元组类型“()”的值没有成员“标签”

我还没有找到任何方法来获取 Swift 3 中的当前队列标签。有人可以帮忙吗？

Thanks,
David

UPDATED这是上下文的函数：

public func log(_ message: String,
                tag: String,
                level: Logger.LogLevel,
                userInfo: [String : String]?,
                functionName: StaticString,
                fileName: StaticString,
                lineNumber: Int) {

    var detailedMessage = ""

    let formattedDate = self._dateFormatter.string(from: Date())
    detailedMessage += "\(formattedDate) "

    detailedMessage += "[\(level.description)] "

    if Thread.isMainThread {
        detailedMessage += "[main] "
    } else {
        if let threadName = Thread.current.name , !threadName.isEmpty {
            detailedMessage += "[" + threadName + "] "
        } else if let queueName
            = String(validatingUTF8: DISPATCH_CURRENT_QUEUE_LABEL.label) , !queueName.isEmpty {
            detailedMessage += "[" + queueName + "] "
        } else {
            detailedMessage += "[" + String(format:"%p", Thread.current) + "] "
        }
    }

    let lastPathComponent = NSString(stringLiteral: fileName).lastPathComponent
    detailedMessage += "[" + lastPathComponent + ":" + String(lineNumber) + "] "

    detailedMessage += "\(functionName) "

    let fullMessage = self.messageWithTag(tag, message: message)
    detailedMessage += "> \(fullMessage)"

    NSLog("\(fullMessage)")
}

你可以使用那个方法

let cName = __dispatch_queue_get_label(nil)
let name = String(cString: cName, encoding: .utf8)