overriding virtual function return type differs and is not covariant

Question

Ah, SO came back just in time.

I am getting a strange error:

 \'B::blah\': overriding virtual function return type differs and is not covariant from          


        

Answer 1

Why is that?

Simply because the ISO C++ standard committee ruled it that way!

There is no fundamental reason. It could be done differently, at the cost of a tiny additional compiler complexity.