Problem with dynamic_cast

Problem with dynamic_cast

[Markus Gerwinski]

Hello,

the following test program refuses to compile:


  #include <iostream>
  #include <typeinfo>


  class Pruzzel {
  }; // Pruzzel


  class Proe: public Pruzzel {
  }; // Proe


  int main ( int argc, char** argv ) {
    Pruzzel *schale = new Proe ();
    if ( Proe *kern = dynamic_cast < Proe* > ( schale ) ) {
      std::cout << "Amazooka" << std::endl;
    } else {
      std::cout << ":-6" << std::endl;
    } // if
  } // main


When trying to build it with "g++ test.cc -o test", I get the error message:

  test.cc: In function `int main(int, char**)':
  test.cc:15: cannot dynamic_cast `schale' (of type `class Pruzzel*') to type `
     class Proe*' (source type is not polymorphic)

What am I doing wrong here?

Thanks in advance,

  Markus

Re: Problem with dynamic_cast

[Momchil Velikov]

>>>>> "Markus" == Markus Gerwinski <markus@gerwinski.de> writes:

    Markus>   test.cc: In function `int main(int, char**)':
    Markus>   test.cc:15: cannot dynamic_cast `schale' (of type `class Pruzzel*') to type `
    Markus>      class Proe*' (source type is not polymorphic)

It needs at least one ``virtual'' function, e.g.

  ``virtual ~Pruzzel () {}''.  

~velco

Re: Problem with dynamic_cast

[Markus Gerwinski]

Momchil Velikov wrote:
>     Markus>   test.cc: In function `int main(int, char**)':
>     Markus>   test.cc:15: cannot dynamic_cast `schale' (of type `class Pruzzel*') to type `
>     Markus>      class Proe*' (source type is not polymorphic)
> It needs at least one ``virtual'' function, e.g.
>   ``virtual ~Pruzzel () {}''.  

Thanks, that did it.

  Markus