C++: A Dialog Programming with the C++ Standard Library

Answers to Exercises

1.

This one was a little tricky. I'll bet you thought that making the default constructor private would keep this from compiling, but it turns out that we're not using the default constructor. That should be obvious in the line string n("Test");, which clearly uses string::string(char* p), but what does the compiler do with the line string x = n;? You might think that it calls the default constructor to make x and then uses operator = to copy the value of n into it. If that were true, the private status of the default constructor would prevent the program from compiling. However, what actually happens is that the copy constructor string::string(const string&) is used to make a brand new string called x with the same value ...