Changing Actions Midstream

Because the Objection appoint() and ignore() operations return the previous value of the action associated with that Objection, a user can change an action for a particular section of a program, saving the previous value, and then restore the old value at a later point. For instance, suppose a client programmer wants to invoke the default action for the Stack::overflow Objection just for the duration of some subroutine. The subroutine can then be written as follows:

      int subroutine()
      {
          Objection_action* save_action;
          save_action = Stack::overflow.appoint();
           // body of the function
          Stack::overflow.appoint(save_action);
      }