About type_id::create()

OVM
5

Hi all,

 I have written a small code snippet. what i expect from it is just to run with out having any errors.
 It is simulating fine when i have used the macro which is commented in the code.
 But it is showing error when iam running it by placing the typedef statement.

module top;

    `include "ovm.svh"

     class scoreboard extends ovm_component;

          // `ovm_component_utils(scoreboard)
          typedef ovm_component_registry #(scoreboard, "scoreboard") type_id;
 
          function void new(input string name = "scoreboard",
                                        input ovm_component parent = null);
                  super.new(name, parent);
          endfunction

     endclass : scoreboard

     scoreboard scb;

     initial begin
          //scb = new();
          scb = scoreboard::type_id::create("scoreboard", this);
     end

endmodule

Error:

 typedef class scoreboard;
 The class specified in the typedef is never declared.

How this can be solved?

Thank you in advance,
mpurna.