Running function with ifstream and stringstream multiple times

Im fairly new to c++ and i would like to ask for suggestions / advice if there is a better / more optimal way to use a function calling ifstream and string stream.

I have a document with the structure with 150 lines and 8 columns (a small subset with values simplified):

5.43e-08    0.0013  0.0105  0.013   0.026   0.068   0.216   0.663
6.98e-08    0.0004  0.0188  0.022   0.103   0.854   0   0
7.31e-08    0.0004  0.0125  0.017   0.074   0.895   0   0
5.82e-08    0.0006  0.0596  0.075   0.150   0.713   0   0

the number of each line represents a position (pos 1 ... pos 150) and each column is a probability of a quality (Qual1 .. Qual8). My goal is to sample from each line being a quality distribution to create a string of qualities for the 150 positions. I have created a function which can do this.

std::string Qual(std::ifstream &infile){
  
  std::string line;
  double Q_1,Q_2,Q_3,Q_4,Q_5,Q_6,Q_7,Q_8;
  char Qualities[] = {'1', '2', '3', '4' ,'5', '6', '7','8','\0'};
  std::string Read_qual;

  while (std::getline(infile, line)){
    std::stringstream ss(line);
    ss >> Q_1 >> Q_2 >> Q_3 >> Q_4 >> Q_5 >> Q_6 >> Q_7 >> Q_8;
    
    std::srand(std::time(nullptr));
    std::random_device rd;
    std::default_random_engine gen(rd());
    std::discrete_distribution<> d({Q_1,Q_2,Q_3,Q_4,Q_5,Q_6,Q_7,Q_8});

    Read_qual += Qualities[d(gen)];
  }
  return Read_qual;
}

The problem is that I have to use this function repeatedly to create multiple of these distributions based on some other input. And as far as I can read here on stack overflow I have to use .clear() and seekq to keep the file open but still use it.

int main(int argc,char **argv){
  std::ifstream infile("Freq.txt");
  std::cout << Qual(infile) << std::endl;
  infile.clear();
  infile.seekg(0);
  std::cout << "-------" << std::endl;
  std::cout << Qual(infile);
  return 0;
}

My question is: Is there a more ideal solution to accomplish this when using c++. Like any functions which are perhaps faster. Could anyone come with any suggestions? is it better to keep opening and closing the file?