[vtkusers] Use of SetExecuteMethod

[camilo.jimenez at spymac.com]

I am trying to use the vtkProgrammableFilter in c++ but I haven't come with 
the use of SetExecuteMethod.

The Help says
void vtkProgrammableFilter::SetExecuteMethod (void (*f)(void *), 
                                                                         void*arg)

so I tried

void func(void){
}

and

filter->SetExecuteMethod(func)  //like the tcl example
 
and other things like that, but I couldn't compile it.

Can somebody help me.
ThanX