C++ Primer Plus

Back to Stringbad: Where the Copy Constructor Goes Wrong

You are now in a position to understand the twofold weirdness of Listing 12.3. (Let’s assume that the output is the one shown after the listing.) The first weirdness is that the program output indicates two more objects destroyed than constructed. The explanation is that the program does create two additional objects, using the default copy constructor. The copy constructor is used to initialize the formal parameter of callme2() when that function is called, and it is used to initialize the object sailor to sports. The default copy constructor doesn’t vocalize its activities, so it doesn’t announce its creations, and it doesn’t increment the num_strings counter. However, the destructor ...