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 derived classes must implement.

Can you give me an example of an abstract class?

Sure! Here's a simple example:

class Shape {
public:
    virtual void draw() = 0; // Pure virtual function
};

class Circle : public Shape {
public:
    void draw() override {
        // Implementation for drawing a circle
    }
};

What should I avoid when designing abstract classes?

Avoid adding non-pure virtual functions that can lead to ambiguity in derived classes. Also, don't make the abstract class too complex; keep it focused on a specific interface.

How do I ensure my abstract class is extensible?

To ensure extensibility, use composition over inheritance where possible, and keep the interface stable. This allows derived classes to add functionality without modifying the base class.