Add missing typedef ctype from base class

dune/subgrid/subgrid/subgridintersection.hh

@@ -88,6 +88,7 @@ class SubGridLeafIntersection :
 
     // The type of the actual local geometry implementation
     typedef SubGridLocalGeometry<dim-1, dimworld, GridImp> LocalGeometryImpl;
+    using ctype = Base::ctype;
 
     using Base::insideIntersect_;
 
@@ -203,7 +204,7 @@ public:
     }
 
     /*! @brief Return unit outer normal at the center of the intersection geometry */
-    FieldVector<typename GridImp::ctype, dimworld> centerUnitOuterNormal () const
+    FieldVector<ctype, dimworld> centerUnitOuterNormal () const
     {
         if (neighbor() and (outside_.level() > inside_.level())) {
             auto normal = outsideIntersect_.centerUnitOuterNormal();