enum E: Int, Codable {
    case one
}

func saveCodableToUserDefaults<T: Codable>(_ object: T, forKey key: String) {
    do {
        // note that we could use either PropertyListEncoder or JSONEncoder, we decided for JSONEncoder - do never change, or old data will not be able to be read again
        let data = try JSONEncoder().encode(object)
        UserDefaults.standard.set(data, forKey: key)
    }
    catch {
        assertionFailure()
    }
}

saveCodableToUserDefaults(E.one, forKey: "test") // assertionFailure