Codable UserDefaults PropertyWrapper

CodableUserDefaultsPropertyWrapper.swift

@propertyWrapper
struct CodableUserDefault<Value: Codable> {
  let key: String
  
  var wrappedValue: Value? {
    get {
      UserDefaults.standard.data(forKey: key).flatMap {
        try? JSONDecoder().decode(Value.self, from: $0)
      }
    }
    nonmutating set {
      let data = try? JSONEncoder().encode(newValue)
      UserDefaults.standard.setValue(data, forKey: key)
    }
  }
  
  var projectedValue: Self { self }
  
  func removeValue() {
    UserDefaults.standard.removeObject(forKey: key)
  }
}

struct Foo: Codable {
  let bar: Int
  let baz: Bool
  let quux: String
}

// MARK: Usage
enum UserDefaultValues {
  @CodableUserDefault(key: "MyApp.myKey")
  static var someValue: Foo?
}

let foo = Foo(bar: 1, baz: true, quux: "hello world")
UserDefaultValues.someValue = foo
UserDefaultValues.$someValue.removeValue()