conc_cast_cases_updown_null_static_dynamic

class Parent ;
virtual task disp ();
    $display(" This is class Parent ");
  endtask
endclass

class Child extends Parent ;
  task disp ();
    $display(" This is class Child ");
  endtask
endclass

program main ;
  Parent P;
  Child C;

  initial
    begin
      C = new();
      $display(" DEBUG: MASTER: step1: doing P = C ");
      P=C;
      $display(" DEBUG: MASTER: step2: calling P.disp() ");
      P.disp();
      $display(" DEBUG: MASTER: step3: calling C.disp() ");
      C.disp();
      $display(" DEBUG: MASTER: step4: doing C=null ");
      C=null;
      $display(" DEBUG: MASTER: step5: doing $cast(C,P) ");
      $display(" $cast(C,P) = %b ",$cast(C,P));
      //##C=P;          //##static cast is not working !!!???
      $cast(C,P);       //##dynamic cast is working
      //##C=P;          //##static cast is not working !!!???
      $display(" DEBUG: MASTER: step6: calling C.disp() ");
      C.disp();
    end
endprogram

//## DEBUG: MASTER: run results
/*
ncsim> run
 DEBUG: MASTER: step1: doing P = C 
 DEBUG: MASTER: step2: calling P.disp() 
 This is class Child 
 DEBUG: MASTER: step3: calling C.disp() 
 This is class Child 
 DEBUG: MASTER: step4: doing C=null 
 DEBUG: MASTER: step5: doing $cast(C,P) 
 $cast(C,P) = 00000000000000000000000000000001 
 DEBUG: MASTER: step6: calling C.disp() 
 This is class Child 
Simulation complete via implicit call to $finish(1) at time 0 FS + 1
./conc_cast_updown_null_static_dynamic.sv:13 program main ; 
ncsim> exit
*/