userdefaults+subscript-5.swift

extension UserDefaults {
    
    subscript<T: RawRepresentable>(key: String) -> T? {
        get {
            if let rawValue = value(forKey: key) as? T.RawValue {
                return T(rawValue: rawValue)
            }
            return nil
        }
        set {
            set(newValue?.rawValue, forKey: key)
        }
    }
}

class SettingsService {
    
    var appTheme: AppTheme {
        get {
            return UserDefaults.standard[#function] ?? .light
        }
        set {
            UserDefaults.standard[#function] = newValue
        }
    }
}