message: HdlDirection_toString: throw std::runtime_error instead cost char *
diff: @@ -28,7 +28,7 @@ inline const char* HdlDirection_toString(HdlDirection d) {
  case DIR_INTERNAL:
  return "INTERNAL";
  default:
  - throw "Invalid direction value";
  + throw std::runtime_error("Invalid direction value");
  }
  }
  