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

Chapter 19. Enforcing Rules for Derived Classes

Difficulty: 5

Too many times, just being at the top of the (inheritance) world doesn't mean that you can save programmers of derived classes from simple mistakes. But sometimes you can! This Item is about safe design of base classes, so that derived class writers have a more difficult time going wrong.

JG Questions

1. When are the following functions implicitly declared and implicitly defined for a class, and with what semantics? Be specific, and describe the circumstances under which the implicitly defined versions cause the program to be illegal (not well-formed).

   1. default constructor

   2. copy constructor

   3. copy assignment operator

   4. destructor

2. What functions are implicitly declared and implicitly defined for the ...