UserDefaults Property Wrapper

Wrap any Codable value so it transparently reads and writes to UserDefaults.

@propertyWrapper
struct UserDefault<T: Codable> {
    let key: String
    let defaultValue: T

    var wrappedValue: T {
        get {
            guard let data = UserDefaults.standard.data(forKey: key),
                  let decoded = try? JSONDecoder().decode(T.self, from: data)
            else { return defaultValue }
            return decoded
        }
        set {
            let data = try? JSONEncoder().encode(newValue)
            UserDefaults.standard.set(data, forKey: key)
        }
    }
}

// Usage
struct Settings {
    @UserDefault(key: "isDarkMode", defaultValue: false)
    static var isDarkMode: Bool
}