23 design patterns in C++ code

Here are 23 design patterns in C++ code:

1. Singleton pattern
2. Factory pattern
3. Abstract Factory pattern
4. Builder pattern
5. Prototype pattern
6. Adapter pattern
7. Bridge pattern
8. Filter pattern
9. Composite pattern
10. Decorator pattern
11. Facade pattern
12. Flyweight pattern
13. Proxy pattern
14. Chain of Responsibility pattern
15. Command pattern
16. Interpreter pattern
17. Iterator pattern
18. Mediator pattern
19. Memento pattern
20. Observer pattern
21. State pattern
22. Strategy pattern
23. Template pattern

Note: These design patterns are language-agnostic and can be implemented in any object-oriented programming language, including C++. The code snippets for each pattern may vary slightly, but the core concepts and design principles remain the same.