c++ - What are some 'good use' examples of dynamic casting?

Question

We often hear/read that one should avoid dynamic casting. I was wondering what would be 'good use' examples of it, according to you?

Edit:

Yes, I'm aware of that other thread: it is indeed when reading one of the first answers there that I asked my question!

Answer 1

This recent thread gives an example of where it comes in handy. There is a base Shape class and classes Circle and Rectangle derived from it. In testing for equality, it is obvious that a Circle cannot be equal to a Rectangle and it would be a disaster to try to compare them. While iterating through a collection of pointers to Shapes, dynamic_cast does double duty, telling you if the shapes are comparable and giving you the proper objects to do the comparison on.

Vector iterator not dereferencable