Operator Overloading with member function or friend
We have three distinct ways ( styles ) of overloading.
1 ) Object + Object
For Example,
Complex operator + ( Complex b ) ;
It will imply that you are adding two objects of class Complex and the result is also of class Complex.
C = A + B ; // A object invokes operator + ( ) function
2 ) Object + basic data type ( say int )
For Example,
classA operator + ( int m ) ;
This poses no problem.
C = A + 15 ; // A object invokes operator + ( ) function
3 ) Basic data type + Object
This poses problem as basic data type is not a class.
C = 15 + A ; // 15 cannot invoke operator + ( ) function
The solution is to use a friend function.
A declaration will take the form:
friend classA operator + ( int m, classA a ) ;
C = 15 + A ; // ok friend function takes all arguments explicitly
