Exceptional C++ Style 40 New Engineering Puzzles, Programming Problems, and Solutions

Chapter 18. Virtuality

Difficulty: 7

In this Item, we delve into old questions with new and/or improved answers. The up-to-date answers to two recurring questions about virtual functions lead directly to four guidelines targeting robust class design. These guidelines answer these questions: why should interfaces be nonvirtual? why should virtuals be private? and what's with the old and hoary advice about base class destructors, and is the old hoary advice really true?

JG Question

1. What is the “common advice” about base class destructors?

Guru Question

1. When should virtual functions be public, protected, or private? Justify your answer, and demonstrate existing practice.

Solution

In this Item, I want to present up-to-date answers to two recurring questions ...