Generate unique elements in an array

UVM
11

Following constraint will generate the unique values in array.

module unique_array;
class data_cl;
  rand bit [7:0] data[];
  constraint data_values { foreach(data[i]) 
                             foreach(data[j])
                               if(i != j) data[i] != data [j] ;} 
endclass

  data_cl cl_ob;

  initial
  begin
     cl_ob = new();
     cl_ob.data = new[20];
     assert(randomize(cl_ob));
     foreach(cl_ob.data[i])
      $display("%d",cl_ob.data[i]);
  end
endmodule