Old problem with performance

[Weed]

Kagamin пишет:
> Weed Wrote:
> 
>>> Well, D class code here is not equivalent to C++ class code. D code has more features, namely, it's polymorphic: C.opAdd is able to work with classes, derived from C, while corresponding C++ code is unable to do so.
>> It is really true?
> 
> Of course.
> 

 But I do not understand in what here problem. In C++ is impossible to
do overloading with "virtual" keyword?
Probably I badly know C ++, sorry.