C++ function overloading is much like Java's. Overloaded functions must differ by parameter type; differences in return type won't help. Default parameters provide an additional wrinkle, since a function with default parameters essentially counts as several overloaded functions, one for each signature with which it can be called.

Which of the following may be added?

int fred(int x, string y);

int fred(double d);

double fred(string z, int q);

void fred(string cc);

int fred(int m, double d = 0.0);