dwg_version_type (const Dwg_Version_Type version)
{
  switch (version)
    {
    case R_INVALID:
      return "invalid version";
    case R_1_1:
      return "r1.1";
    case R_1_2:
      return "r1.2";
    case R_1_3:
      return "r1.3";
    case R_1_4:
      return "r1.4";
    case R_1_402b:
      return "r1.402b";
    case R_2_0:
      return "r2.0";
    case R_2_1:
      return "r2.1";
    case R_2_21:
      return "r2.21";
    case R_2_22:
      return "r2.22";
    case R_2_4:
      return "r2.4";
    case R_2_5:
      return "r2.5";
    case R_2_6:
      return "r2.6";
    case R_9:
      return "r9";
    case R_9c1:
      return "r9c1";
    case R_10:
      return "r10";
    case R_10c1:
      return "r10c1";
    case R_10c2:
      return "r10c2";
    case R_11:
      return "r11";
    case R_12:
      return "r12";
    case R_12c1:
      return "r12c1";
    case R_13:
      return "r13";
    case R_13c3:
      return "r13c3";
    case R_14:
      return "r14";
    case R_2000:
      return "r2000";
    case R_2004:
      return "r2004";
    case R_2007:
      return "r2007";
    case R_2010:
      return "r2010";
    case R_2013:
      return "r2013";
    case R_2018:
      return "r2018";
    case R_AFTER:
      return "invalid after";
    default:
      return "";
    }
}
dwg_version_type (const Dwg_Version_Type version)
{
  switch (version)
    {
    case R_INVALID:
      return "invalid version";
    case R_1_1:
      return "r1.1";
    case R_1_2:
      return "r1.2";
    case R_1_3:
      return "r1.3";
    case R_1_4:
      return "r1.4";
    case R_1_402b:
      return "r1.402b";
    case R_2_0:
      return "r2.0";
    case R_2_1:
      return "r2.1";
    case R_2_21:
      return "r2.21";
    case R_2_22:
      return "r2.22";
    case R_2_4:
      return "r2.4";
    case R_2_5:
      return "r2.5";
    case R_2_6:
      return "r2.6";
    case R_9:
      return "r9";
    case R_9c1:
      return "r9c1";
    case R_10:
      return "r10";
    case R_10c1:
      return "r10c1";
    case R_10c2:
      return "r10c2";
    case R_11:
      return "r11";
    case R_12:
      return "r12";
    case R_12c1:
      return "r12c1";
    case R_13:
      return "r13";
    case R_13c3:
      return "r13c3";
    case R_14:
      return "r14";
    case R_2000:
      return "r2000";
    case R_2004:
      return "r2004";
    case R_2007:
      return "r2007";
    case R_2010:
      return "r2010";
    case R_2013:
      return "r2013";
    case R_2018:
      return "r2018";
    case R_AFTER:
      return "invalid after";
    default:
      return "";
    }
}