Method val_decimal

sql/item_func.h:1056–1063

    return (longlong) rint(Item_func_udf_float::val_real());
  }
  my_decimal *val_decimal(my_decimal *dec_buf)
  {
    double res=val_real();
    if (null_value)
      return NULL;
    double2my_decimal(E_DEC_FATAL_ERROR, res, dec_buf);
    return dec_buf;
  }
  double val_real();
  String *val_str(String *str);
};