C++ Primer Plus

Which Method?

In addition to introducing changes in class constructor rules, MI often requires other coding adjustments. Consider the problem of extending the Show() method to the SingingWaiter class. Because a SingingWaiter object has no new data members, you might think the class could just use the inherited methods. This brings up the first problem. Suppose you do omit a new version of Show() and try to use a SingingWaiter object to invoke an inherited Show() method:

SingingWaiter newhire("Elise Hawks", 2005, 6, soprano);newhire.Show();  // ambiguous

With single inheritance, failing to redefine Show() results in using the most recent ancestral definition. In this case, each direct ancestor has a Show() function, which makes this call ambiguous. ...