How to compile programm with error "no matching function for call to 'to_string'"? c++

Question

If I have here DATA_T = std::string, I can't compile this code, because of error "no matching function for call to 'to_string'". The function does not allow converting a string to a string. But I need to get the string anyway, how can I work around this error and compile the program?

template <typename DATA_T>
std::string get_string(DATA_T subdata) {
  std::string data = "...";
  if (typeid(subdata) == typeid(std::string))
    data += subdata;
  else
    data += std::to_string(subdata);
  return data;
}

Answer 1

Instead of trying to branch on the type of a template argument inside the body of your function, you can write an overload that will be preferred when the argument is a std::string.

template <typename DATA_T>
std::string get_string(DATA_T subdata) {
  std::string data = "...";
  data += std::to_string(subdata);
  return data;
}

std::string get_string(std::string subdata)
{
  std::string data = "...";
  data += subdata;
  return data;
}