Compile error when map to normal type

Elements C#
4

  1. I’m confused…In my discussion with marc (Mapped class to wrapped value types can’t work as expected), the mapping to int? is disabled because marc thinks nullable is a modifier instead of a specific type.
    But here Nullable and java.lang.Integer are specific types.

  2. I’ve also explained the use case in my origin post:
    Mapped class to wrapped value types can’t work as expected