C++ In a Nutshell

Operator Overloading

For user-defined types (classes and enumerations), you can define alternate behavior for the C++ operators. This is called overloading the operators. You cannot define new operators, and not all operators can be overloaded. Table 5-2 lists all the operators and indicates which can be overloaded. For these, it shows whether the overload must be a member function. Overloaded operators that are implemented as member functions must be nonstatic member functions.

Table 5-2. Operators and overloading

Operator	Meaning	Overloading permitted?	Must be member function?
+	Addition, unary plus	yes	no
&	Address of	yes	no
[]	Array subscript	yes	yes
&=	Assign bitwise and	yes	no
^=	Assign bitwise exclusive or	yes	no
|=	Assign bitwise or	yes	no
-=	Assign difference	yes	no
<<=	Assign left shift	yes	no
=	Assignment	yes	yes
*=	Assign product	yes	no
/=	Assign quotient	yes	no
%=	Assign remainder	yes	no
>>=	Assign right shift	yes	no
+=	Assign sum	yes	no
&	Bitwise and	yes	no
~	Bitwise complement	yes	no
^	Bitwise exclusive or	yes	no
|	Bitwise or	yes	no
? :	Conditional	no	N/A
new	Create dynamic object	yes	no
new[]	Create dynamic array	yes	no
--	Decrement	yes	no
delete	Destroy dynamic object	yes	no
delete[]	Destroy dynamic array	yes	no
/	Division	yes	no
==	Equal	yes	no
( )	Function call	yes	yes
>	Greater than	yes	no
>=	Greater than or equal	yes	no
++	Increment	yes	no
<<	Left shift	yes	no
<	Less than	yes	no
<=	Less than or equal	yes	no
&&	Logical and	yes	no
!	Logical complement	yes	no
||	Logical or	yes	no
.*	Member reference	no	N/A
->*	Member reference	yes	yes
.	Member ...