RTTI - Notes - typeid

type_id:
In C++, the typeid keyword is used to determine the class of an object at runtime.

#include <iostream>
#include <typeinfo>  //for 'typeid' to work
 
class Person {
public:
   // ... Person members ...
   virtual ~Person() {}
};
 
class Employee : public Person {
   // ... Employee members ...
};
 
int main () {
   Person person;
   Employee employee;
   Person *ptr = &employee;
   // The string returned by typeid::name is implementation-defined
   std::cout << typeid(person).name() << std::endl;   // Person (statically known at compile-time)
   std::cout << typeid(employee).name() << std::endl; // Employee (statically known at compile-time)
   std::cout << typeid(ptr).name() << std::endl;      // Person * (statically known at compile-time)
   std::cout << typeid(*ptr).name() << std::endl;     // Employee (looked up dynamically at run-time
                                                      //           because it is the dereference of a
                                                      //           pointer to a polymorphic class)
}