title: Swift encode tuple using NSCoding
body: <p>Is it possible to store a tuple using <code>NSCoding</code>? I have a tuple like <code>((UInt8, UInt8), (UInt8, UInt8))</code>. But <code>aCoder.encodeObject(myTuple)</code> doesn't work. Do I have to convert the tuple into <code>NSData</code> or is this absolutely not possible? Thanks for any help</p>