What are the best practices for using abstract classes in C++?

What are the best practices for using abstract classes in C++?

When using abstract classes in C++, it's important to ensure that they define a clear interface. This means only including pure virtual functions that subclasses must implement.

Can you give me an example of a pure virtual function?

Sure! A pure virtual function is declared by assigning 0 in its declaration. For example: virtual void draw() = 0; in an abstract class Shape.

How do I ensure that my derived classes implement these functions?

You can enforce implementation by making the base class abstract. If a derived class does not implement all pure virtual functions, it will also be abstract and cannot be instantiated.

Are there any performance considerations I should be aware of?

Yes, using abstract classes can introduce a slight overhead due to virtual function calls. However, this is often negligible compared to the benefits of code organization and flexibility.