From: Magdalena Schreter <schreter.magdalena@gmail.com>
Date: Fri, 5 Mar 2021 18:32:19 +0000 (+0100)
Subject: improve assert in FEFaceEvaluation
X-Git-Tag: v9.3.0-rc1~371^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F11854%2Fhead;p=dealii.git

improve assert in FEFaceEvaluation
---

diff --git a/include/deal.II/matrix_free/fe_evaluation.h b/include/deal.II/matrix_free/fe_evaluation.h
index 45de596e71..0dd7d3d894 100644
--- a/include/deal.II/matrix_free/fe_evaluation.h
+++ b/include/deal.II/matrix_free/fe_evaluation.h
@@ -8493,7 +8493,10 @@ FEFaceEvaluation<dim,
       face_index <
         this->matrix_info->get_task_info().boundary_partition_data.back())
     Assert(this->is_interior_face,
-           ExcMessage("Boundary faces do not have a neighbor"));
+           ExcMessage(
+             "Boundary faces do not have a neighbor. When looping over "
+             "boundary faces use FEFaceEvaluation with the parameter "
+             "is_interior_face set to true. "));
 
   this->face_no =
     (this->is_interior_face ? faces.interior_face_no : faces.exterior_face_no);