Add is_empty()

Polygon/include/CGAL/General_polygon_with_holes_2.h

@@ -123,6 +123,19 @@ public:
 
   bool is_plane() const { return (m_pgn.is_empty() && m_holes.empty()); }
 
+  bool is_empty() const
+  {
+    if(! outer_boundary().is_empty()) {
+        return false;
+      }
+    for(const auto& h : holes()){
+      if(! h.is_empty()){
+        return false;
+      }
+    }
+    return true;
+  }
+
 protected:
   Polygon_2 m_pgn;
   Holes_container m_holes;

Polygon/include/CGAL/Multipolygon_with_holes_2.h

@@ -111,6 +111,15 @@ public:
     return bb;
   }
 
+  bool is_empty() const
+  {
+    for(const auto& pwh : polygons_with_holes()){
+      if(! pwh.is_empty()){
+        return false;
+      }
+    }
+    return true;
+  }
 
 protected:
   Polygon_with_holes_container m_polygons;

Polygon/test/Polygon/Multipolygon_with_holes_test.cpp

@@ -47,5 +47,6 @@ int main()
 
   CGAL::Bbox_2 bb = mp.bbox();
   std::cout << bb << std::endl;
+  assert(! mp.is_empty());
   return 0;
 }

Polygon_repair/include/CGAL/Polygon_repair/repair.h

@@ -314,7 +314,6 @@ public:
   using Face_circulator = typename Triangulation::Face_circulator;
   using Edge = typename Triangulation::Edge;
 
-  // TODO: Edge_map and Vertex_map use std::set and std::map with exact kernels since Point_2 can't be hashed otherwise
   using Edge_map = typename std::conditional<std::is_floating_point<FT>::value,
                                              std::unordered_set<std::pair<Point_2, Point_2>,
                                                                 boost::hash<std::pair<Point_2, Point_2>>>,