Overloading Unary Operators

• Overloading unary operators
  • Non-static member function, no arguments
  • Non-member function, one argument; Argument must be class object or reference to class object
  • Remember, static functions only access static data
• Upcoming example (8.10)
  • Overload ! to test for empty string
  • If non-static member function, needs no arguments
    • !s becomes s.operator!()
    • class String { public: bool operator!() const; ...};
• If non-member function, needs one argument
  • s! becomes operator!(s)
  • class String { friend bool operator!( const String & ) ... }