Object Oriented Programming with C++, Second Edition

18.7 RE-THROWING AN EXCEPTION

Exceptions are caught in a catch clause and processed. Sometimes the catch clause may decide to re-throw this exception. It is allowed if we use third form of throw statement, i.e. throw without any exception specified. The re-thrown exception is not passed to any of the catch clause at that level. It is now passed on to the catch clause at the outer level (if one exists).