bool operator ==(const Cents &c1, const Cents &c2) {
return (c1.cents() == c2.cents());
}
const Cents operator -(const Cents &c) {
return (-c.cents());
}
// This function is NOT a member function!
const Cents operator -(const Cents &c1, const Cents &c2) {
// Use the Cents constructor and operator-(int, int)
return Cents(c1.cents() - c2.cents());
}