Question

config是地图中的地图：

   std::map<std::string, std::map<std::string, std::string>> config;

我正在尝试解析配置文件（.ini）。

所以，

config[sectionName] = map<std::string, std::string>>();
config[sectionName][optionKey] = value; //when option and value store a string.

现在，

我正在尝试实现此功能。我得到错误：一个是“sections == section”和“sections.second ==”false“”无法比较。我收到的错误是“错误：二进制表达式的操作数无效”。

有谁能请解释我有什么问题？

/*
 * Searches for option's value in section and converts it to a bool if possible.
 *
 * If the value isn't one of the options below or if section/option
 * don't exist the conversion fails.
 *
 * Returns a pair of <bool, bool>
 *  first is set to true if conversion succeeded, false otherwise.
 *  If the conversion succeeds, second is the converted boolean value.
 *  If the conversion fails, it doesn't matter what second is set to.
 *
 *  Converts to true: "true", "yes", "on", "1"
 *  Converts to false: "false", "no", "off", "0"
 *
 */
pair<bool, bool> ConfigParser::getBool(const string& section,
    const string& option) const
{
  for(const auto& sections : config){
    if(sections == section && sections.first != ""){

      if(sections.second == "true" || sections.second == "yes" ||
          sections.second == "on" || sections.second == "1"){

        return pair<bool, bool>(true, true);
      }
      if(sections.second == "false" || sections.second == "no" ||
          sections.second == "off" || sections.second == "0"){

        return pair<bool, bool>(true, false);
      }
    }
  }
  return pair<bool, bool>(false, false);
}

Answer 1

考虑你的代码片段：

for(const auto& sections : config) {
     if(sections == section && sections.first != "") {

此处sections为pair<string, map<string, string>>，section为string。

那些不具有可比性。

如果您只想查找section部分，则可以使用更多方式。例如：

pair<bool, bool> ConfigParser::getBool(const string& section,
                                       const string& option) const
{
    auto it = config.find(section);
    if (it == config.end()) { return {false, false}; }

    auto jt = it->second.find(option);
    if (jt == it->second->end()) { return {false, false}; }

    // parse jt->second
    return {true, /* parse result */ };
}

将一对的值与一个字符串进行比较

1 个答案: