add generator function for AnalyticGridFunction

dune/curvedsurfacegrid/gridfunctions/analyticgridfunction.hh

@@ -136,6 +136,12 @@ auto analyticGridFunction (FF&& ff)
   return AnalyticGridFunction<Grid, F>{std::forward<FF>(ff)};
 }
 
+template <class FF, class Grid>
+auto analyticGridFunction (FF&& ff, Grid const& /*grid*/)
+{
+  using F = std::decay_t<FF>;
+  return AnalyticGridFunction<Grid, F>{std::forward<FF>(ff)};
+}
 
 template <class GridType, class Functor>
 class AnalyticGridFunction