About :associative array :class index type

SystemVerilog
,
4

Hi Dave,
I tried it :


module class_var;

class AB;
int a;

endclass
int arr[AB];
AB obj;

initial
begin
arr[obj.a]=20;
$display("%0d\n",arr[obj.a]);
end
endmodule

but it is genrating fatal error,illegal associative array key type