KnownTypeAttribute for C++.NET

[DataContract]
[KnownType(List<String^>::typeid)]
ref class MyClass
{
   [DataMember]
   public List<String^>^ _myStrings;
};

[DataContract]
[KnownType(List<MyClass^>::typeid)]
ref class NewClass
{
   [DataMember]
   public List<MyClass^>^ _myClasses;
};