Add a default implementation for a template method.

diff --git a/source/grid/tria_accessor.cc b/source/grid/tria_accessor.cc
index 74cf9b5fa96e06178dfbefd4e170c847c735154c..0cc240e62356eb45610364e185207c6ae2958dc8 100644 (file)
--- a/source/grid/tria_accessor.cc
+++ b/source/grid/tria_accessor.cc
@@ -1133,6 +1133,15 @@ bounding_box () const
 
 
 
+template <int structdim, int dim, int spacedim>
+double TriaAccessor<structdim, dim, spacedim>::extent_in_direction(const unsigned int /*axis*/) const
+{
+  Assert(false, ExcNotImplemented());
+  return std::numeric_limits<double>::signaling_NaN();
+}
+
+
+
 template <>
 double TriaAccessor<1,1,1>::extent_in_direction(const unsigned int axis) const
 {