我正在尝试将多个子类添加到UITableView中.问题是它一直给我以下错误:

Type UITableVieCell does not conform to protocol NilLiteralConvertible

的cellForRowAtIndexPath

override  func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    if indexPath.section == 0 {

        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell

        cell.textLabel?.text = self.section1[indexPath.row]
        cell.accessoryType = .DisclosureIndicator

        return cell

    } else if indexPath.section == 1 {

        let cell = tableView.dequeueReusableCellWithIdentifier("SwitchViewCell", forIndexPath: indexPath) as SwitchViewCell

        cell.cellLabel?.text = self.section2[indexPath.row]

        return cell
    }

    return nil
}