Binary Operators as Friends

A friend of a class is a function or a class that is given access to the private members of that class.
The class must declare who its friends are.

Write friend Function-prototype; or friend class Class-name; in the class definition.

Write the operator as a non-member function.
The operator has 2 parameters: the left and right operands.
Advantages
- The expressions a + b and b + a are equivalent.
- Only one function call is needed.
Disadvantages
- Friendship violates the data-hiding principle.

This page was last modified on Feb 1, 2001

URL: http://people.hsc.edu/faculty-staff/robbk/Coms262/Lectures/OperatorsFriends.html