rmompati / cos-782-a2 Goto Github PK

This implementation is generic due to several key features that allow it to handle multiple types and operations dynamically:

1. TypeList and Variadic Templates: The TypeList struct combined with variadic templates (template<typename... Types>) allows the program to accept and work with an arbitrary number of types. This flexibility lets you define MultiTypeObserver for any combination of data types without modifying the underlying class structure.

2. Template Specialization: The specialization of MultiTypeObserver for TypeList<Types...> enables the observer to inherit from multiple ObserverInterface<Types> instances. This means a single observer can listen to updates for multiple data types, adhering to each type's specific update method.

3. Observer and Subject Interfaces: Both observer and subject are defined using templates, which makes them adaptable to any data type. This abstraction not only ensures type safety but also enhances reusability and scalability of the code.

4. Use of Shared Pointers: The use of std::shared_ptr for managing observers in SubjectImplementation ensures that memory management is handled automatically, and it's safe to use with different data types without worrying about memory leaks or dangling pointers.

5. Method Overloading and Overrides: The observer methods update(const DataType& data) are overridden for specific data types in ConcreteObserver, demonstrating how the observer can handle different types of data updates specifically.

These features collectively make the implementation highly flexible and adaptable to various data types and scenarios, which is a hallmark of generic programming.

observer -> subject In the Observer Pattern implementation, the interaction between subjects and observers is designed for flexibility and modularity. Observers, such as instances of ConcreteObserver, register with subjects like SubjectImplementation<NaspersStock> to be notified about specific events, such as changes in stock prices. The subject maintains a dynamically managed list of registered observers and, upon an event (e.g., a price update), iterates over this list to notify each observer by invoking their update method with the new data. This method is implemented by each observer to handle the received data appropriately, allowing for customized responses to the same event. Observers have the option to unregister from the subject if they no longer wish to receive updates, which is handled through the removeObserver method, ensuring that the observer is cleanly removed from the subject's notification list. This pattern effectively decouples the state management of the subject from the response behavior of the observers, enabling a system where changes in the subject's state are efficiently propagated to interested parties without requiring tight integration, thereby promoting scalability and maintainability.