change referenceElement in Marker

amdis/Marker.inc.hpp

@@ -282,11 +282,10 @@ Flag GridFunctionMarker<Grid, PreGridFct>::markGrid(AdaptInfo& adaptInfo)
   for (auto const& e : Dune::elements(this->grid_->leafGridView())) {
     localFct.bind(e);
     int currentLevel = e.level();
-    auto geo = e.geometry();
-    auto const& ref = Dune::referenceElement(geo);
+    auto refElem = Dune::referenceElement<typename Grid::ctype,Grid::dimension>(e.type());
 
     // evaluate in the center of the element
-    int targetLevel = int(std::round(localFct(ref.position(0,0))));
+    int targetLevel = int(std::round(localFct(refElem.position(0,0))));
 
     int m =   ((((targetLevel > currentLevel) && (currentLevel < this->maxRefineLevel_))
                   || (currentLevel < this->minRefineLevel_))