fix argt demo

changes in Arrangement_on_surface_2/include/CGAL/Arr_polycurve_traits_2.h
should be undo

Arrangement_on_surface_2/demo/Arrangement_on_surface_2/ArrangementGraphicsItem.cpp

@@ -961,15 +961,16 @@ findOtherInterestingPoints<demo_types::DemoTypes::Alg_seg_arr>
  const CGAL::Bbox_2& allowable_range) {
   using Traits = demo_types::DemoTypes::Alg_seg_traits;
   CGAL::Bbox_2 bb = {};
-  std::vector<CGAL::Object> intersections;
+  typedef std::pair<typename Traits::Point_2, unsigned int> Pt_m;
+  std::vector<Pt_m> intersections;
   for (auto it = arr->edges_begin(); it != arr->edges_end(); ++it) {
     for (auto& arc : getXyCurves(arr->traits()))
+    {
       if (arc.is_vertical() != it->curve().is_vertical())
-        it->curve().intersections(arc, std::back_inserter(intersections));
+        it->curve().intersections(arc, CGAL::dispatch_or_drop_output<Pt_m>(std::back_inserter(intersections)));
+      }
   }
-  for (auto it = intersections.begin(); it != intersections.end(); it++) {
-    std::pair<typename Traits::Point_2, unsigned int> point_multiplicity;
-    CGAL::assign(point_multiplicity, *it);
+  for (auto point_multiplicity :intersections) {
     auto& point = point_multiplicity.first;
     if (point.location() == CGAL::ARR_INTERIOR) {
       auto xy = point.to_double();

Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Utils/IntersectCurves.cpp

@@ -11,6 +11,8 @@
 
 #include "IntersectCurves.h"
 #include "ArrangementTypes.h"
+#include <boost/function_output_iterator.hpp>
+
 
 template <typename Traits_>
 Intersect_curves<Traits_>::Intersect_curves(const Traits* traits) :
@@ -18,12 +20,26 @@ Intersect_curves<Traits_>::Intersect_curves(const Traits* traits) :
 {
 }
 
+struct Object_putter
+{
+  std::vector<CGAL::Object>& v;
+  Object_putter(std::vector<CGAL::Object>& v)
+    : v(v)
+  {}
+
+  template <class T>
+  void operator()(const T& t)
+  {
+    v.push_back(make_object(t));
+  }
+};
+
 template <typename Traits_>
 void Intersect_curves<Traits_>::operator()(
   const X_monotone_curve_2& cv1, const X_monotone_curve_2& cv2,
   std::vector<CGAL::Object>& output)
 {
-  this->intersect(cv1, cv2, std::back_inserter(output));
+  this->intersect(cv1, cv2, boost::make_function_output_iterator(Object_putter(output)));
 }
 
 ARRANGEMENT_DEMO_SPECIALIZE_TRAITS(Intersect_curves)

Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Utils/Utils.cpp

@@ -625,14 +625,14 @@ operator()(const X_monotone_curve_2& curve, const CoordinateType& x,
   Point_2 p2c1(x, CoordinateType(clipRect.ymax() + 1));
 
   const X_monotone_curve_2 verticalLine = ctr_xcv(p1c1, p2c1);
-  CGAL::Object o;
-  CGAL::Oneset_iterator<CGAL::Object> oi(o);
+  std::vector<IntersectionResult> pairs;
 
-  this->intersectCurves(curve, verticalLine, oi);
+  this->intersectCurves(curve, verticalLine,
+    CGAL::dispatch_or_drop_output<IntersectionResult>(std::back_inserter(pairs)));
 
   IntersectionResult pair;
-  if (CGAL::assign(pair, o)) {
-    Point_2 pt = pair.first;
+  if (!pairs.empty()) {
+    Point_2 pt = pairs[0].first;
     res = pt.y();
   }
   return res;
@@ -654,14 +654,13 @@ operator()(const X_monotone_curve_2& curve, const CoordinateType& x,
   Point_2 p2c1(x, CoordinateType(10000000));  // upper bounding box
 
   const X_monotone_curve_2 verticalLine = ctr_xcv(p1c1, p2c1);
-  CGAL::Object o;
-  CGAL::Oneset_iterator<CGAL::Object> oi(o);
+  std::vector<IntersectionResult> pairs;
 
-  this->intersectCurves(curve, verticalLine, oi);
+  this->intersectCurves(curve, verticalLine,
+    CGAL::dispatch_or_drop_output<IntersectionResult>(std::back_inserter(pairs)));
 
-  IntersectionResult pair;
-  if (CGAL::assign(pair, o)) {
-    Point_2 pt = pair.first;
+  if (!pairs.empty()) {
+    Point_2 pt = pairs[0].first;
     res = pt.y();
   }
   return res;
@@ -681,15 +680,15 @@ operator()(const X_monotone_curve_2& curve, const Coordinate_type& x)
   Point_2 p2c1(x, Coordinate_type(clip_rect.ymax() + 1));
 
   const X_monotone_curve_2 vertical_line = ctr_xcv(p1c1, p2c1);
-  CGAL::Object o;
-  CGAL::Oneset_iterator<CGAL::Object> oi(o);
 
-  this->intersect_curves(curve, vertical_line, oi);
+  std::vector<IntersectionResult> pairs;
+
+  this->intersect_curves(curve, vertical_line,
+    CGAL::dispatch_or_drop_output<IntersectionResult>(std::back_inserter(pairs)));
 
   Coordinate_type res(0);
-  IntersectionResult pair;
-  if (CGAL::assign(pair, o)) {
-    Point_2 pt = pair.first;
+  if (!pairs.empty()) {
+    Point_2 pt = pairs[0].first;
     res = pt.y();
   }
   return res;
@@ -708,15 +707,15 @@ auto Arr_compute_y_at_x_2<CGAL::Arr_algebraic_segment_traits_2<Coefficient_>>::
 operator()(const X_monotone_curve_2& curve, const CoordinateType& x)
   -> CoordinateType
 {
-  CGAL::Object o;
-  CGAL::Oneset_iterator<CGAL::Object> oi(o);
   Intersect_2 intersect = traits->intersect_2_object();
   X_monotone_curve_2 c2 = this->makeVerticalLine(x);
-  intersect(curve, c2, oi);
-  std::pair<Point_2, Multiplicity> res;
-  if (CGAL::assign(res, o)) {
+  typedef std::pair<Point_2, Multiplicity> PtM;
+
+  std::vector<PtM> res;
+  intersect(curve, c2, CGAL::dispatch_or_drop_output<PtM>(std::back_inserter(res)));
+  if (!res.empty()) {
     // TODO: handle failure case
-    const Point_2& p = res.first;
+    const Point_2& p = res[0].first;
     CoordinateType coord = p.y();
     return coord;
   }

Arrangement_on_surface_2/include/CGAL/Arr_polycurve_traits_2.h

@@ -826,7 +826,7 @@ public:
               std::get_if<X_monotone_subcurve_2>(&xection);
             if (subcv_p != nullptr) {
               ocv.push_back(*subcv_p);
-              oi = output_ocv (ocv, invert_ocv, oi);
+              output_ocv (ocv, invert_ocv, oi);
               continue;
             }
 
@@ -883,7 +883,7 @@ public:
             // An overlap occurred at the previous iteration:
             // Output the overlapping polycurve.
             CGAL_assertion(ocv.size() > 0);
-            oi = output_ocv (ocv, invert_ocv, oi);
+            output_ocv (ocv, invert_ocv, oi);
           }
           else {
             // The left point of the current subcurve of one
@@ -929,7 +929,7 @@ public:
 
         // Output the remaining overlapping polycurve, if necessary.
       if (ocv.size() > 0) {
-        oi = output_ocv (ocv, invert_ocv, oi);
+        output_ocv (ocv, invert_ocv, oi);
       }
       else if (right_coincides) {
         typedef std::pair<Point_2,Multiplicity> return_point;