undefined reference to typeinfo for [class name]

[sajis997]

Hi Forum

There are many explanations for this type of error , but none of them made much sense to me. I have subclassed a class and over-ridden the virtual method as follows:

   void Context::operator() (osg::GraphicsContext *gc)
   {
            ......................
            ......................

                       osgViewer::GraphicsWindowX11 *unixWindow = dynamic_cast<osgViewer::GraphicsWindowX11*>(gc);

           if(unixWindow == NULL)
           {
                osg::notify(osg::FATAL) << __FUNCTION__ << ": " << __LINE__ << ": "
                                        << "Unix Graphics Handle Casting is not successful. " << std::endl;


                exit(EXIT_FAILURE);

           }

             ...............................
             ...............................
   }

And i am getting the following error

../../../lib/libosgOpenCLd.so: undefined reference to `typeinfo for osgViewer::GraphicsWindowX11'
collect2: ld returned 1 exit status
make[2]: *** [bin/osgOpenCLEndiannessDemod] Error 1
make[1]: *** [examples/osgOpenCLEndiannessDemo/src/CMakeFiles/example_osgOpenCLEndiannessDemo.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
 

Any idea folks ?


Thanks
Sajjad