Empty abstract base class

[AleaIactaEst]

Is it possible to declare an empty class (without any member functions or variables) ?

I need it to make a linked list containing different classes.

Any better ideas to achive this in another way with or without using polymorphism are welcome :)

[Athar]

Is it possible to declare an empty class (without any member functions or variables) ?

Yes, although that's not very useful if you don't make it polymorphic.

different classes

Elaborate.