README.md

Class Level Exceptions

Class-level exceptions are a method of encapsulating the exception handling mechanism within a class. This approach can enhance the modularity and maintainability of exception handling by localizing the concerns of error detection and management within the classes that are responsible for those errors.

Rationale

Utilizing class-level exceptions allows:

• Encapsulation: Keeping the exception-related code within the class that throws them.
• Reusability: When a class with its own exceptions is reused, the exceptions are reused automatically.
• Abstraction: Hiding the complexity of error handling from the users of the class.

Designing Class Level Exceptions

When designing exceptions for a class, it's essential to consider:

1. Which operations could fail: Constructors, methods, or even destructors could potentially fail and may need to throw exceptions.
2. What kind of failure could occur: Different methods might fail for different reasons, and it may be useful to have distinct exception types for each kind of failure.
3. Inheritance hierarchy: It can be beneficial for all exceptions in a class hierarchy to inherit from a common base exception specific to that hierarchy.

Implementing Class Level Exceptions

Implementation involves creating one or more exception classes within or associated with the class that will throw them. Here's a conceptual overview of how it might look:

Example Class with Its Own Exception

class MyResource {
public:
    // Define a nested class-level exception type
    class ResourceException : public std::exception {
    private:
        std::string message;
    public:
        ResourceException(const std::string& msg) : message(msg) {}
        const char* what() const noexcept override {
            return message.c_str();
        }
    };

    MyResource() {
        // Constructor code that might throw a ResourceException
    }

    void doSomething() {
        // Method code that might throw a ResourceException
    }
};

In the example above, MyResource has a nested ResourceException class. This design makes it clear that ResourceException is intended to be used solely in conjunction with MyResource.

Using Class Level Exceptions

Using the class and handling its exceptions can be done as follows:

int main() {
    try {
        MyResource resource;
        resource.doSomething();
    } catch (const MyResource::ResourceException& e) {
        std::cerr << "MyResource error: " << e.what() << std::endl;
    }
    return 0;
}

The main function demonstrates how to catch class-level exceptions. The catch block specifically handles exceptions of the type MyResource::ResourceException.

Benefits of Class Level Exceptions

• Clarity: The origin and context of an exception are clearer because the exception is tied to the class.
• Maintainability: As the class evolves, its exceptions can be modified in parallel without affecting other parts of the codebase.
• Safety: Sensitive information can be protected by carefully controlling what is included in the exception message.

Conclusion

Class-level exceptions are a structured way to manage errors in object-oriented programming. By defining exceptions that are specific to a class, you can create a more robust and self-contained error-handling strategy that is easier to understand and maintain.