Inheriting Itself?

Identifying design patterns in C++ code

This is an easy design patterns question testing your ability to recognise one of the fundamental patterns from the Gang of Four catalogue when you see it in a concrete C++ implementation. Questions like this appear in technical screens and phone interviews to verify that you can map abstract pattern concepts to actual code.

To answer correctly, you need to understand the structural or behavioural intent of the pattern—what problem it solves and how the code elements (inheritance, composition, method delegation) work together to achieve that intent. Pay close attention to the relationships between classes and what role each one plays in the overall design.

• Creational patterns (abstract factories, builders, singletons)
• Structural patterns (adapters, decorators, proxies, bridges)
• Behavioural patterns (observers, strategies, commands, visitors)