text: #include <CGAL/Simple_cartesian.h>
  #include <CGAL/Kd_tree.h>
  #include <CGAL/Search_traits_2.h>
  #include <CGAL/point_generators_2.h>
  #include <CGAL/algorithm.h>
  #include <CGAL/Fuzzy_sphere.h>
  
  typedef CGAL::Simple_cartesian<double> K;
  typedef K::Point_2 Point;
  typedef CGAL::Random_points_in_square_2<Point> Random_points_iterator;
  typedef CGAL::Counting_iterator<Random_points_iterator> N_Random_points_iterator;
  typedef CGAL::Search_traits_2<K> Traits;
  typedef CGAL::Fuzzy_sphere<Traits> Fuzzy_circle;
  typedef CGAL::Kd_tree<Traits> Tree;
  typedef CGAL::Random Random;
  
  int main() {
  
    const int N=1000;
  
    // generator for random data points in the square ( (-1,-1), (1,1) )
    Random rnd(0);
    Random_points_iterator rpit(1.0, rnd);
  
    // Insert also the N points in the tree
    Tree tree(N_Random_points_iterator(rpit,0),
  			      N_Random_points_iterator(N));
  
    // define exact circular range query
    Point center(0.2, 0.2);
    Fuzzy_circle exact_range(center, 0.2);
  
    boost::optional<Point> any = tree.search_any_point(exact_range);
    if(any){
      std::cout << *any << " is in the query circle\n";
    }else{
      std::cout << "Empty query circle\n";
    }
    std::list<Point> result;
    tree.search(std::back_inserter( result ), exact_range);
  
    std::cout << "\nPoints in cirle with center " << center << " and radius 0.2" << std::endl;
  
    std::list<Point>::iterator it;
    for (it=result.begin(); (it != result.end()); ++it) {
      std::cout << *it << std::endl;
    }
  
    result.clear();
    // approximate range searching using value 0.1 for fuzziness parameter
    Fuzzy_circle approximate_range(center, 0.2, 0.1);
  
    tree.search(std::back_inserter( result ), approximate_range);
  
    std::cout << "\n\nPoints in cirle with center " << center << " and fuzzy radius [0.1,0.3]" << std::endl;
  
    for (it=result.begin(); (it != result.end()); ++it) {
      std::cout << *it << std::endl;
    }
    std::cout << "\ndone" << std::endl;
    return 0;
  }
  