text: #include <fstream>
  #include <vector>
  #include <string>
  
  template <class PointMassList, class Point>
  void load_xy_file(const std::string& filename, PointMassList& points)
  {
    std::ifstream ifs(filename.c_str());
    Point point;
    while (ifs >> point)
      points.push_back(std::make_pair(point, 1));
  
    ifs.close();
  }
  
  template <class Point>
  void load_xy_file_points(const std::string& fileName, std::vector<Point>& points)
  {
    std::ifstream ifs(fileName.c_str());
    Point point;
    while (ifs >> point)
    {
      points.push_back(point);
    }
    ifs.close();
  }
  