#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"; } 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; }
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