dynamiccast.cpp

Think in C++ 第二版源码

//: C24:DynamicCast.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Using the standard dynamic_cast operation
#include <cassert>
#include <typeinfo>
using namespace std;

class D1 { 
public:
  virtual void func() {} 
  virtual ~D1() {}
};

class D2 { 
public:
  virtual void bar() {} 
};

class MI : public D1, public D2 {};
class Mi2 : public MI {};

int main() {
  D2* d2 = new Mi2;
  Mi2* mi2 = dynamic_cast<Mi2*>(d2);
  MI* mi = dynamic_cast<MI*>(d2);
  D1* d1 = dynamic_cast<D1*>(d2);
  assert(typeid(d2) != typeid(Mi2*));
  assert(typeid(d2) == typeid(D2*));
} ///:~