Hmm, shouldn't it be possible to do that in some other way? After all, a virtual function is something different than a function pointer (the vtable holding a function pointer is only an implementation detail, isn't it?).

Anyway, I'd rather not have that optimization. When we don't want to pay a small performance hit, we shouldn't make a virtual function in the first place. It's good to see how advanced optimization tricks can combine in dangerous ways with complicated language features!

> distinguish it from non-silly examples?

Yes, probably not possible. There is a real risk, but non-silly examples are less likely than constructed ones.

> all hidden by some #ifdef

If you do it with the preprocessor, there is no need for function pointers in the first place. Just make a #define instead of a variable.

Thanks again for the example, very interesting!