#include <iostream>

class A
{
·       public:
·       ·       A() {}
·       ·       virtual ~A() {}
};

class B : public A
{
};

int main()
{
·       B* b = new B;
·       A* a = b;
·       std::cout << typeid( a ).name() << std::endl;
·       std::cout << typeid( b ).name() << std::endl;
·       return 0;
}

mkretz@Epsilon3% g++ typeid.cpp
mkretz@Epsilon3% ./a.out
P1A
P1B