Exceptions

Any runtime error generates an exception. Exceptions terminate the execution. It is possible to catch an exception instead of terminating the execution:

    auto e;
    try
    {
      ... some statements that cause a runtime error...
    }
    catch ( e )
    {
      // e holds the exception information
      // it is an instance of the exception class
    }

See the details of classes.

The try/catch blocks can be nested. If the current function has no try/catch blocks, the calling function will be examined, and so on, until we find a try/catch block or exit the main function. If no try/catch block is found, an unhandled exception is reported.

It is also possible to throw an exception explicitly. Any object can be thrown. For example:

    throw 5;

will throw value ‘5’.