What is an exception ?

• An object of any copy-able type can be an exception:

      #include <iostream>
      void main() {
          try {
              throw 20;
          }
          catch ( int ex ) {
              std::cout << "Exception occurred: " << ex;
          }
      }

• Avoid using native types: int, bool, and so on.

• Often classes are created specifically for exceptions.

• The STL provides several exception types.