dynamic_cast bug? Feature?

[Bruce Ide <nride at uswest dot net>]

I've got a bit of C++ code here that exits with a compiler error in GCC
2.95.2. Shouldn't this compile and have dynamic_cast return a 0 for the
class the compiler's erroring on?

-- 
Bruce Ide                        nride@uswest.net
If trees screamed would we be as quick to cut them down? Possibly,
if they screamed all the time.
#include <iostream>
#include <string>

class Pinger {
public:
  Pinger() {};
  virtual ~Pinger() {};

  virtual void ping() { cout << " Ping" << endl; } ;
};

class CanPing1 : public Pinger {
   public:
   CanPing1(char *data) {my_data.append(data);}
   ~CanPing1() {};

   string my_data;
};

class CanPing2 : public Pinger {
   public:
   CanPing2(char *data) {my_data.append(data);}
   ~CanPing2() {};

   string my_data;
}; 

class CantPing {
   public:
   CantPing(char *data) {my_data.append(data);}
   ~CantPing() {}

  string my_data;
};

template <typename T> void ping(T *object)
{
 Pinger *s;

 s = dynamic_cast<Pinger *>(object);
 if (s) {
    s->ping();
 } else {
    cout << " can't ping" << endl;
 }
}

int main()
{
 CanPing1 first("CanPing1");
 CanPing2 second("CanPing2");
 CantPing third("CantPing");
 cout << first.my_data;
 ping(&first);
 cout << second.my_data;
 ping(&second);
 cout << third.my_data;
 ping(&third);
}