class Grand{ //has virtual methods};
class Super:public Grand {...}
class Magnificent : public Superb{...}

Grand *pg = new Grand ;
Grand *ps = new Superd;
Grand *pm = new Manificent;

Superb pm = dynamic_cast< Superb > (pg) ; 

// test1002.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <cstdlib>
#include <ctime>
#include<iostream>

using std::cout;
class Grand
{
private:
  int hold;
public :
  Grand(int h = 0) :hold(h) {}
  virtual void Speak() const { cout << "I am a grand class \n"; }
  virtual int Value() const { return hold; }
};

class Superb :public Grand
{
public :
  Superb(int h = 0) :Grand(h) {}
  void Speak() const { cout << "I am a superb class ! \n"; }
  virtual void Say() const 
  {
    cout << "I hold the superb value of " << Value() << "! \n";
  }
};

class Magnificent : public Superb
{
private :
  char ch;
public :
  Magnificent(int h = 0, char c = 'A') :Superb(h), ch(c)
  {
  }
  void Speak() const 
  {
    cout << "I am a magnificent class !!!! \n";
  }
  void Say() const
  {
    cout << "I hold the character " << ch << " and the integer " << Value() <<"! \n";
  }
};

Grand * GetOne();
int main()
{
  std::srand(static_cast<unsigned int>(std::time(0)));
  Grand * pg;
  Superb * ps;
  for (int i = 0; i < 5; i++)
  {
    pg = GetOne();
    pg->Speak();
    if (ps = dynamic_cast<Superb *>(pg)) {
      ps->Say();
    }
  }
  system("pause");
  return 0;
}
Grand * GetOne()
{
  Grand * p = new Grand();
  switch (std::rand() % 3)
  {
    delete p;
  case 0:p = new Grand(std::rand() % 100); break;
  case 1:p = new Superb(std::rand() % 100); break;
  case 2:p = new Magnificent(std::rand() % 100, std::rand() % 26); break;
  }

  return p;
}
运行结果:
I am a superb class !
I hold the superb value of 3!
I am a magnificent class !!!!
I hold the character   and the integer 5!
I am a grand class
I am a grand class
I am a magnificent class !!!!
I hold the character   and the integer 87!
请按任意键继续. . .

// test1002.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <cstdlib>
#include <ctime>
#include<iostream>
#include <typeinfo>
using std::cout;
class Grand
{
private:
  int hold;
public :
  Grand(int h = 0) :hold(h) {}
  virtual void Speak() const { cout << "I am a grand class \n"; }
  virtual int Value() const { return hold; }
};

class Superb :public Grand
{
public :
  Superb(int h = 0) :Grand(h) {}
  void Speak() const { cout << "I am a superb class ! \n"; }
  virtual void Say() const 
  {
    cout << "I hold the superb value of " << Value() << "! \n";
  }
};

class Magnificent : public Superb
{
private :
  char ch;
public :
  Magnificent(int h = 0, char c = 'A') :Superb(h), ch(c)
  {
  }
  void Speak() const 
  {
    cout << "I am a magnificent class !!!! \n";
  }
  void Say() const
  {
    cout << "I hold the character " << ch << " and the integer " << Value() <<"! \n";
  }
};

Grand * GetOne();
int main()
{
  std::srand(static_cast<unsigned int>(std::time(0)));
  Grand * pg;
  Superb * ps;
  for (int i = 0; i < 5; i++)
  {
    pg = GetOne();
    cout << "Now Process type " << typeid (*pg).name() << ". \n"; //显示
    pg->Speak();
    if (ps = dynamic_cast<Superb *>(pg)) {
      ps->Say();
    }
  }
  system("pause");
  return 0;
}
Grand * GetOne()
{
  Grand * p = new Grand();
  switch (std::rand() % 3)
  {
    delete p;
  case 0:p = new Grand(std::rand() % 100); break;
  case 1:p = new Superb(std::rand() % 100); break;
  case 2:p = new Magnificent(std::rand() % 100, std::rand() % 26); break;
  }

  return p;
}
运行结果:
Now Process type class Superb.
I am a superb class !
I hold the superb value of 86!
Now Process type class Grand.
I am a grand class
Now Process type class Superb.
I am a superb class !
I hold the superb value of 48!
Now Process type class Grand.
I am a grand class
Now Process type class Magnificent.
I am a magnificent class !!!!
I hold the character and the integer 75!
请按任意键继续. . .