Sebastien Loriot

I gave a try with your meshes in the demo and I could compute the output of the union, intersection and difference successfully. The mesh I get is valid but...

For parts using only input points, EPICK is used. As soon as a construction occurs, an internal exact representation is stored and used for answering exactly predicates involving those points.

> Do you agree that [here](https://github.com/CGAL/cgal/blob/7570ad8a43994b2890f0172293f48e69ca803672/Surface_mesh_deformation/include/CGAL/Surface_mesh_deformation.h#L568) we cannot replace because it is something that can happen ? assertion should be removed

> Does it make sense to have an assertion in [`TDS_3::is_valid()`](https://github.com/CGAL/cgal/blob/7570ad8a43994b2890f0172293f48e69ca803672/TDS_3/include/CGAL/Triangulation_data_structure_3.h#L3595)? I would remove it

> > > Do you agree that [here](https://github.com/CGAL/cgal/blob/7570ad8a43994b2890f0172293f48e69ca803672/Surface_mesh_deformation/include/CGAL/Surface_mesh_deformation.h#L568) we cannot replace because it is something that can happen ? > > > > > > assertion should be removed >...

> > > > > Do you agree that [here](https://github.com/CGAL/cgal/blob/7570ad8a43994b2890f0172293f48e69ca803672/Surface_mesh_deformation/include/CGAL/Surface_mesh_deformation.h#L568) we cannot replace because it is something that can happen ? > > > > > > > > >...

> Would this also compile if the static function [here ](https://github.com/CGAL/cgal/blob/418b00e27469c6ed8b2539242e5158d5ece072ca/Surface_mesh_topology/include/CGAL/Surface_mesh_topology/internal/Functors_for_face_graph_wrapper.h#L42) was just removed? After all we need the class only because of the offered specializations. Indeed, you should get...

> [Here](https://github.com/CGAL/cgal/blob/50219fc33bc53b5846e9a4257befc6baef3f395a/Convex_decomposition_3/include/CGAL/Convex_decomposition_3/Single_wall_creator.h#L257) we have the assertion as first line of a function. git blame says that the code is 16yo and from Peter. So basically it was always there. We...

> @sloriot any idea what the function [`initialize_index_map()`](https://github.com/CGAL/cgal/blob/119bd102c9f8d77dc80d09f827381c504dba1490/BGL/include/CGAL/boost/graph/internal/initialized_index_maps_helpers.h#L84) is about? I do not see it used anywhere. Do we have it for backward compatibility? probably a leftover after some refactoring.

@efifogel could you please have a look?