[Libmesh-users] Testing if element is on boundary

[<lu...@gi...>]

Hi

Maybe a stupid question: Why is the following construct used in all
the examples to determine that an element lives on the boundary?

   for (unsigned int s=0; s<elem->n_sides(); s++)
     if (elem->neighbor(s) == NULL)

Would'nt this be faster / more obvious if one would use

   if (elem->on_boundary())

and then use the boundary side iterators (Elem::boundary_sides_begin)?

Thanks for clarification

Martin