C＃禁止上传

Question

Is there a way to prohibit implicit upcast of a paticular class ?

I want the compiler to throw an error if a function accepting MyBase is passed an instance of MyDerived (same for assignment etc)

My use case is trying immitate c++ typedef by inheriting but upcasting break this.

Answer 1

No. You can't do that on compile time. It is a derived class after all. It it its purpose to do so. You can on run time, but I don't think you want that.

You can make MyBase sealed if you don't want any derived type to exist.

I do wonder why you would want this, but that is a whole different question...