Re: On C++ multiple inheritance

[Jorrit Tyberghein <jorrit.tyberghein@xxxxxxxxxxxxxxxxx>]

Miguel A. Osorio wrote:

> Hey people,
>
>
>     I'm currently in the process of doing some changes to my renderer 
> and I'll probably adding some new classes into the existing hierarchy. 
> At this time, I do make some *light* use of multiple inheritance and 
> haven't had any problems with it yet, nor do I detect any problems 
> arising from changes or additions I'll be making to the hierarchy.
>
>     *But*, I have noticed that quite a large number of programmers 
> declare multiple inheritance as something to be "avoided like the 
> plague", and although I can relate to that if I imagine a badly 
> designed hierarchy using that mechanism, I'm not really sure of the 
> reasons behind negative arguments like that.

Multiple inheritance can be dangerous in C++ because it can cause subtle 
bugs that are very hard to catch.
Most of these bugs have to do with wrong pointer offsetting when casting 
from one of the inherited classes
to the parent cast and vice versa.

If you only use pure virtual abstract classes (the interfacing idea like 
already presented in this list)
then the use of multiple inheritance is not that bad.

Greetings,