I am writing some C++ code for a web application, and there I am handling errors via exception. There are two broad types of exceptions, one that is internal an

I am writing some C++ code for a web application, and there I am handling errors via exception. There are two broad types of exceptions, one that is internal and one that needs to be reported to the user. Following is how I an handling the errors, please could you all suggest a better approach if my approach is sub-optimal designwise? // Base class HandleRequest(req, res) { try { try { post_processing(req, res) // implemented by derived class process_request(req, res) // implemented by derived class pre_processing(req, res) // implemented by derived class } catch(send_to_user_exception) { send_error_to_user(send_to_user_exception.what()) // implemented by derived class } } catch(internal_exception) { log_error(internal_exception.what()) send_internal_error_to_user(internal_exception.what()) // implemented by derived class } catch(unknown_exception) { log_error(unkown_exception.what()) send_internal_error_to_user(unkown_exception.what()) // implemented by derived class } } // Each request type is handled by its corresponding derived class and implements the following methods of the base class. post_processing(req, res) // will throw exceptions of type send_to_user_exception and internal_exception process_request(req, res) // will throw exceptions of type send_to_user_exception and internal_exception pre_processing(req, res) // will throw exceptions of type send_to_user_exception and internal_exception send_error_to_user(error) send_internal_error_to_user(error)