Function Overloading

Reading: Dietel section 3.20

• C++ allows more than one implementation of a given function name
        Applies to member functions within the same class and nonmember functions
• Want to allow the same type of operation for different types of arguments
        int power ( int base, int exponent );
        double power ( int base, double exponent );
        Rational power ( Rational base, double exponent );
• Versions are differentiated by :
        Number / type of parameters
        Const function vs. non-const function
        Const vs. non-const parameter(s)
        Rules for default parameters still apply
• When compiler encounters a call, parameter list is used to find best match
         Exact match of parameter list
         Const version called on const objects, non-const on non-const
         Const-parameter version used with const-type reference parameters, etc.
• Cannot overload by return type only!
         Syntax error
         Compiler will not know which version to call
• Caution: make sure versions are distinguishable ( especially with default parameters )
         int myfunc ( double x, int y = 0 );
         int myfunc ( double x, double y = 1.0);
  
         int a = myfunc ( 8.7, 2 );  // First version called
         int b = myfunc ( 8.7, 2.4 );  // Second version called
         int x = myfunc ( 8.7 );   // Which version should be called?  Syntax error!