From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Fri, 29 Apr 2016 21:42:49 +0000 (-0500)
Subject: Improve an error message.
X-Git-Tag: v8.5.0-rc1~1064^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F2565%2Fhead;p=dealii.git

Improve an error message.
---

diff --git a/include/deal.II/numerics/vector_tools.templates.h b/include/deal.II/numerics/vector_tools.templates.h
index 66980c7505..dbf4030aab 100644
--- a/include/deal.II/numerics/vector_tools.templates.h
+++ b/include/deal.II/numerics/vector_tools.templates.h
@@ -2343,7 +2343,12 @@ namespace VectorTools
                       level = cell->level();
                     else
                       {
-                        Assert (level == cell->level(), ExcNotImplemented());
+                        Assert (level == cell->level(),
+                                ExcMessage("The mesh you use in projecting boundary values "
+                                           "has hanging nodes at the boundary. This would require "
+                                           "dealing with hanging node constraints when solving "
+                                           "the linear system on the boundary, but this is not "
+                                           "currently implemented."));
                       }
                   }
               }