How should runtime errors be handled in C++?

The runtime errors can be handled using the C++ exceptions. The purpose of the C++ exception-handling mechanism is to handle errors in software composed of independently developed components operating in a single process and under synchronous control.
In C++, a routine that cannot fulfill its promises should throw an exception. The caller that knows how to handle this unusual situation can catch the thrown exception. Callers can specify the types of exceptions they are willing to handle; exceptions that don't match the specified types are automatically propagated to the caller's caller. Thus intermediate callers (between the thrower and the catcher) can simply ignore the exception. Only the original thrower and the ultimate catcher need to know about the unusual situation.