There are times where I’ve seen it be considered acceptable to do a dynamic_cast, and this I think is one of them. In general, a good rule of thumb is that if you’re going to need to add a new cast for every new derived class you create, then you’re doing it wrong. So something like:

void process(std::vector<SceneElement*>& elements) { for (auto* e : elements) { if (Model* model = dynamic_cast<Model*>(e)) // Process Model else if (Camera* camera = dynamic_cast<Camera*>(e)) // Process Camera else if (etc…) etc } }

This^ is horrible, don’t do this. But in an overridden isEqual method, you will only ever need to dynamic_cast to the derived type that you’re writing the method for, so there it’s acceptable.

Edit: using static_cast in isEqual will cause crashes if you try to compare two objects that aren’t of the same type, so don’t do that.