Operator overloading is an important concept in C++. It is a type of polymorphism in which an operator is overloaded to give user defined meaning to it. Overloaded operator is used to perform operation on user-defined data type. For example '+' operator can be overloaded to perform addition on various data types, like for Integer, String(concatenation) etc.
Almost any operator can be overloaded in C++. However there are few operator which can not be overloaded. Operator that are not overloaded are follows
Operator overloading can be done by implementing a function which can be :
Operator overloading function can be a member function if the Left operand is an Object of that class, but if the Left operand is different, then Operator overloading function must be a non-member function.
Operator overloading function can be made friend function if it needs access to the private and protected members of class.
Following are some restrictions to be kept in mind while implementing operator overloading.