The binary relational operators:
, <=, ==, !=, > and >=
may be extendible to user defined data types They would not be meaningful on the complex class but they would be as member operators on the Date class.
if(date1 <= 12/31/2006) cout << "The date was before the end of 2006" << endl;
Notice how these operators are using in the following program: datereln.cpp
Observe that the output of each of these relational operations in this program is not a class object but a variable of the bool data type. Thus the explicit argument and the output are not required to be class objects and can be any data type.