《C++ Standard Library》notes

 

Chapter 3. General Concepts

3.3.1 Standard Exception Classes

l          Standard exception classes can be divided into three groups:

1.      Exceptions for language support

2.      Exceptions for the C++ standard library

3.      Exceptions for errors outside the scope of a program

 

l          std::bad_exception

           class E1;

   class E2;

   void f() throw(E1)       //throws only exceptions of type E1

   {

       ...

       throw E1();          //throws exception of type E1

       ...

       throw E2();          //calls unexpected(), which calls terminate()

   }

if class bad_exception is part of the exception specification, then unexpected() usually rethrows an exception of this type:

 class E1;

   class E2;

   void f() throw(E1, std::bad_exception)

                          //throws exception of type El or

                          //bad_exception for any other exception type

   {

      ...

      throw E1();         //throws exception of type E1

      ...

      throw E2();         //calls unexpected(), which throws bad_exception

   }