I\'m using NSJSONSerialization as so:
let twData: AnyObject? = NSJSONSerialization.JSONObjectWithData(responseData, options: NSJSONReadingOption
This works in a playground:
var data: Array>? = twData as? Array>
the difference from your code is that twData does not require the ? at the end - it is an optional so the as? operator will take care of verifying that it can be case to an array of dictionaries - needless to say, if it's nil, as? will evaluate to nil