read .txt file

/*-------------------------------------------------Read .txt file-------------------------------------------------*/void ReadTxt(std::string fileStr){std::ifstream file(fileStr);std::string s;while (getline(file,s)){std::vector<double> vec;int start = 0, end = 0;while(end!=s.size()){if (s[end]==' '){string str;str = s.substr(start, end-start);double v = std::stod(str);vec.push_back(v);start = end+1;}end++;}}}