cpp/CPPlusV6/Chapter 15/rtti2.cpp

// rtti2.cpp  -- using dynamic_cast, typeid, and type_info
#include <iostream>
#include <cstdlib>
#include <ctime>
#include <typeinfo>
using namespace std;

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 cv = 'A') : Superb(h), ch(cv) {}
    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()
{
    srand(time(0));
    Grand * pg;
    Superb * ps;
    for (int i = 0; i < 5; i++)
    {
        pg = GetOne();
        cout << "Now processing type " << typeid(*pg).name() << ".\n";
        pg->Speak();
        if( ps = dynamic_cast<Superb *>(pg))
            ps->Say();
        if (typeid(Magnificent) == typeid(*pg))
            cout << "Yes, you're really magnificent.\n";
    }
    // std::cin.get();
    return 0;
}

Grand * GetOne()
{
    Grand * p;

    switch( rand() % 3)
    {
        case 0: p = new Grand(rand() % 100);
                    break;
        case 1: p = new Superb(rand() % 100);
                    break;
        case 2: p = new Magnificent(rand() % 100, 'A' + rand() % 26);
                    break;
    }
    return p; 
}