c – g警告：无符号表达式的比较<0始终为false

我认为这被视为一个错误,并在GCC 4.3版本上得到修复,但我使用的是GCC 4.1

代码显然@L_@R_673_11235@_4@冒犯：

void FieldGroup::generateCreatemessage (const ApiEvent::Groupdata &data,omsgstream &result) const {
  dblog << debug;

  // Write out the data fields we care about,in the order they were specified
  for (size_t index = 0; index < fields.size(); ++indeX) {
    size_t esIndex = clsToES[index];
    if (esIndex < 0 || esIndex >= data.fields.length()) {
      oStringstream buf;
      buf << "Invalid field " << index << " (index in ES data set " << esIndex << "," << data.fields.length() << " fields returned)";
      throw InvalidDataException (buf.str());
    }
    fields[index].writeData (data.fields[esIndex],result);
  }
}

警告我得到：

我怎么可能阻止这些警告出现？我不想删除-W标志.