NSKeyedArchiverとNSKeyedUnarchiverにCodable対応のメソッドが追加されてたのね。 https://developer.apple.com/documentation/foundation/nskeyedarchiver/2924373-encodeencodable?changes=latest_beta https://developer.apple.com/documentation/foundation/nskeyedunarchiver/2924375-decodetopleveldecodable?changes=latest_beta