- std::string key = dnPart.substr(0, pos);
- std::string value = dnPart.substr(pos + 1, dnPart.length() - pos + 1); // +1s to skip the = itself
+ std::string key(dnPart, 0, pos);
+ std::string value(dnPart, pos + 1, dnPart.length() - pos + 1); // +1s to skip the = itself