null

  #include <iostream>
    #include <fstream>
    using namespace std;
    
    int main () {
      forward_list<int> FL;
      ofstream myfile;
      myfile.open ("testlist.txt");
     if (myfile.is_open())
  {
    while ( getline (myfile,line) )
    {
      FL.push_front(line);
    }
    myfile.close();
  }
    }

但没起作用。如有任何帮助，我将不胜感激

我有:

#include <iostream>
#include <fstream>
#include <string>
#include <forward_list>
#include<iterator>
using namespace std;

int main () {
  forward_list<int> FL;
  string line;
  ifstream myfile ("list.txt");
  if (myfile.is_open())
  {
    forward_list<int> FL(istream_iterator<int>(myfile), istream_iterator<int>());
  }

else{
    cout<<"error file";
}
  for(forward_list<int>::iterator i=FL.begin(); i!=FL.end(); ++i)
    cout<<*i<<" ";
  return 0;
}

但它什么都没有