C++ Primer, Fifth Edition

13.2. Copy Control and Resource Management

Ordinarily, classes that manage resources that do not reside in the class must define the copy-control members. As we saw in § 13.1.4 (p. 504), such classes will need destructors to free the resources allocated by the object. Once a class needs a destructor, it almost surely needs a copy constructor and copy-assignment operator as well.

In order to define these members, we first have to decide what copying an object of our type will mean. In general, we have two choices: We can define the copy operations to make the class behave like a value or like a pointer.

Classes that behave like values have their ...