From 813de2e5e6d98b68929d74a93b869ce600b20a50 Mon Sep 17 00:00:00 2001 From: Wolfgang Bangerth Date: Wed, 13 Sep 2017 07:42:15 -0600 Subject: [PATCH] Explain a code example better. --- include/deal.II/distributed/grid_tools.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/include/deal.II/distributed/grid_tools.h b/include/deal.II/distributed/grid_tools.h index ad3edeb35a..319c70ee7d 100644 --- a/include/deal.II/distributed/grid_tools.h +++ b/include/deal.II/distributed/grid_tools.h @@ -110,10 +110,18 @@ namespace parallel * (dof_handler, pack, unpack); * @endcode * - * You will notice that the lambda function returns an `unsigned int`, + * You will notice that the @p pack lambda function returns an `unsigned int`, * not a `boost::optional`. The former converts automatically * to the latter, implying that data will always be transported to the * other processor. + * + * (In reality, the @p unpack function needs to be a bit more + * complicated because it is not allowed to call + * DoFAccessor::set_active_fe_index() on ghost cells. Rather, the + * @p unpack function directly accesses internal data structures. But + * you get the idea -- the code could, just as well, have exchanged + * material ids, user indices, boundary indictors, or any kind of other + * data with similar calls as the ones above.) */ template void -- 2.39.5