Codable+.swift

extension KeyedEncodingContainer {
    public mutating func encode<T>(_ value: T, forKey key: KeyedEncodingContainer<K>.Key) throws where T : NSCoding {
        let data = try NSKeyedArchiver.archivedData(withRootObject: value, requiringSecureCoding: false)
        try encode(data, forKey: key)
    }
}


extension KeyedDecodingContainer {
    public func decode<T>(_ type: T.Type, forKey key: KeyedDecodingContainer<K>.Key) throws -> T? where T : NSCoding {
        let data = try decode(Data.self, forKey: key)
        return try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? T ?? nil
    }
}