title: Comparing non-optional Any to nil is always false?
body: <p>I'm iterating through a dictionary of <code>[String: Any]</code>, looking for <code>nil</code>s, so I can replace them with <code>NSNull</code> for a JSON write. My precompiler warning is telling me that comparing an <code>Any</code> to a <code>nil</code> will always be false, but I know it contains at least two nils which are never found. Is there a way to check is an <code>Any</code> is nil? </p>