Mael

@afabri what is the status of this PR?

The `CGAL::halfedges_around_target` already gives you sorted halfedges around the target: it is merely calling `opposite(next())` to go from one halfedge to the next. The only difference between a boundary halfedge...

The `halfedges_around_target` starts from `halfedge(v, g)`. If `v` is a border vertex, for CGAL structures then the incident edge is a border edge (this was wrong: this is for CGAL::Seam_mesh...

Can you please provide a self contained example?

A c++ example would be better, please

> If v is a border vertex, for CGAL structures then the incident edge is a border edge I remembered wrongly: it's only for a specific CGAL graph class, CGAL::Seam_mesh....

Changing the clamped / non-clamped of the cotan had some positive effects, see September weeks in https://cgalwiki.geometryfactory.com/CGAL/Members/wiki/GSoC2024/Mollification.

@sloriot @afabri 2490190 and feae9aa need reviewing. Former is to get `CGAL::Iso_rectangle_2::Rep::first_type` and `CGAL::Getter` to play nice together. Latter is because `const CGAL::Getter::first_type&...` gives a `const&` and then it doesn't...

Simply: ```cpp FT lower_bound = square(FT(error_bound)); CGAL_precondition(sq_initial_bound >= lower_bound); ``` ?

You are probably using a CGAL::Surface_mesh and getting the number of elements through [`num_vertices()`](https://doc.cgal.org/latest/BGL/classVertexListGraph.html#a77e742c910da6a8230a45273186b130b) and similar functions. As [the doc](https://doc.cgal.org/latest/BGL/classVertexListGraph.html#a77e742c910da6a8230a45273186b130b) indicates: > [num_vertices()](https://doc.cgal.org/latest/BGL/classVertexListGraph.html#a77e742c910da6a8230a45273186b130b) may return a number larger than std::distance(vertices(g).first,...