fix read_PLY and add a test to bgl for the ply writing

BGL/include/CGAL/boost/graph/IO/PLY.h

@@ -43,8 +43,9 @@ namespace CGAL {
 template <class FaceGraph, class NamedParameters>
 bool write_PLY(std::ostream& out,
                const FaceGraph& mesh,
-               const NamedParameters& np,
-               const std::string& comments = std::string())
+               const std::string& comments,
+               const NamedParameters& np
+               )
 {
   typedef typename boost::graph_traits<FaceGraph>::vertex_descriptor          vertex_descriptor;
   typedef typename boost::graph_traits<FaceGraph>::halfedge_descriptor        halfedge_descriptor;
@@ -109,12 +110,27 @@ bool write_PLY(std::ostream& out,
   return out.good();
 }
 
+template <class FaceGraph>
+bool write_PLY(std::ostream& out,
+               const FaceGraph& mesh,
+               const std::string comments)
+{
+  return write_PLY(out, mesh, comments, parameters::all_default());
+}
+
+template <class FaceGraph, typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
+bool write_PLY(std::ostream& out,
+               const FaceGraph& mesh,
+               const CGAL_BGL_NP_CLASS& np)
+{
+  return write_PLY(out, mesh, "", np);
+}
 
 template <class FaceGraph>
 bool write_PLY(std::ostream& out,
                const FaceGraph& mesh)
 {
-  return write_PLY(out, mesh, parameters::all_default(), "");
+  return write_PLY(out, mesh, "", parameters::all_default());
 }
 
 } // namespace CGAL

BGL/test/BGL/test_bgl_read_write.cpp

@@ -206,12 +206,24 @@ bool test_PLY()
   CGAL::make_tetrahedron(Point(0, 0, 0), Point(1, 1, 0),
                          Point(2, 0, 1), Point(3, 0, 0), fg);
   std::ostringstream out;
-  CGAL::write_PLY(out, fg);
+  CGAL::write_PLY(out, fg, "hello");
   if(out.fail())
   {
     std::cerr<<"Tetrahedron writing failed."<<std::endl;
     return false;
   }
+  std::istringstream in(out.str());
+  std::vector<Point> points;
+  std::vector<std::vector<std::size_t> > polygons;
+
+  if(!CGAL::read_PLY(in, points, polygons)){
+    std::cerr<<"Tetrahedron reading failed."<<std::endl;
+    return false;
+  }
+
+  CGAL_assertion(points.size() == 4);
+  CGAL_assertion(polygons.size() == 4);
+
   return true;
 }
 

Stream_support/include/CGAL/IO/PLY.h

@@ -245,7 +245,7 @@ read_PLY(std::istream& is,
         IO::internal::process_properties(element, new_vertex,
                                           make_ply_point_reader(CGAL::Identity_property_map<Point_3>()));
 
-        points.push_back(get<0>(new_vertex));
+        points.push_back(new_vertex);
       }
     }
     else if(element.name() == "face" || element.name() == "faces")