Virtual inheritance in C++ usages/tricks [closed]

Question

I've never used it in the professional software even though in our shop, and others I have worked for, we design large scale systems. The only time I messed with virtual inheritance was during my interview in a company. Nonetheless, I played with it during afterhours.

Do you guys use it? Do you understand how it works in depth (how most popular compiler vendors implement it)? I would really like to know how it is used in professional software, if at all. Tricks and tips would be appreciated, too.

To me, virtual inheritance was just a solution to an infamous diamond problem. Hence, it never found its way in our software, as we don't have in our architecture MI resulting in the diamond.

Thanks.

Answer 1

The main point with virtual inheritance is to prevent derived classes from inheriting multiple copies of different superior classes. This can occur in any case where there may be multiple inheritance -- as you correctly note, the "diamond problem", which is to say where the inheritance graph is a DAG instead of a strict tree.

The C++ FAQ goes into it in some detail. I'd also recommend the C++ FAQ Book; I used to work for the authors and they're quite good.