c++ function pointers

fncptr.cpp

#include <iostream>

class BaseClass
{
protected:
    std::string id;
public:
    BaseClass(std::string id)
    {
        this->id = id;
    }

    virtual void printId(void) = 0;

};

class ExtendedClass1 : BaseClass
{
public:
    ExtendedClass1(std::string id) : BaseClass(id) {}

    void printId(void)
    {
        std::cout << "The id from 1 is '" << id.c_str() << "'\n";
    }
};

class ExtendedClass2 : BaseClass
{
public:
    ExtendedClass2(std::string id) : BaseClass(id) {}

    void printId(void)
    {
        std::cout << "The id from 2 is '" << id.c_str() << "'\n";
    }
};


int main(void)
{
    // Create two classes
    ExtendedClass1 *e1 = new ExtendedClass1("class 1");
    ExtendedClass2 *e2 = new ExtendedClass2("class 2");

    // Create function pointer
    void (BaseClass::*fncPtr)(void) = &BaseClass::printId;

    // Pointer to hold two classes
    BaseClass *storedPtr = NULL;

    // Test class 1
    storedPtr = (BaseClass *)e1;
    (storedPtr->*fncPtr)();

    // Test class 2
    storedPtr = (BaseClass *)e2;
    (storedPtr->*fncPtr)();

    std::getchar();

    return 0;
}