Run time type identification. 

through typeid operator we can justify object at run time.

RTTI> Run Time Type Identification

RTTI means during time of run object property can be
retrieve and changed. Under RTTI dynamic_cast<>, typeid,
const_cast<> etc are used.

Run Time Type Information ( RTTI ) : Run-time type 
information (RTTI) is a mechanism that allows the type of 
an object to be determined during program execution.

	There are three main C++ language elements to run-
time type information: 
The dynamic_cast operator : Used for conversion of 
polymorphic types.

		The typeid operator : Used for identifying 
the exact type of an object.
The type_info class : Used to hold the type information 
returned by the typeid operator.