Add some documentation

dune/subgrid/subgrid/subgridintersection.hh

@@ -157,10 +157,13 @@ public:
 
         return *this;
     }
+
+    //! Return inside element
     Entity inside() const {
         return inside_;
     }
 
+    //! Return outside element, throws exception for boundary elements
     Entity outside() const {
         if (!neighbor())
             DUNE_THROW(GridError, "There is no neighbor!");
@@ -186,6 +189,7 @@ public:
                                                 : outsideIntersect_.indexInInside();
     }
 
+    //! Return GeometryType of the intersection
     GeometryType type () const {
         if (outside_.level() > inside_.level())
             return outsideIntersect_.type();
@@ -214,6 +218,7 @@ public:
             return insideIntersect_.centerUnitOuterNormal();
     }
 
+    //! Return the global geometry of the intersection
     Geometry geometry () const {
         if (outsideIntersect_.inside().level() >= insideIntersect_.inside().level())
             return Geometry(GeometryImpl(outsideIntersect_.geometry()));