diff --git a/src/lib/access-casted.hpp b/src/lib/access-casted.hpp
index 1880f3709..eff197e4b 100644
--- a/src/lib/access-casted.hpp
+++ b/src/lib/access-casted.hpp
@@ -54,25 +54,22 @@ namespace util {
   using std::remove_pointer;
   using std::remove_reference;
   
+  namespace error = lumiera::error;
+  
+  template <typename T>
+  using PlainType = typename remove_pointer<
+                    typename remove_reference<T>::type>::type;
   
   template <typename T>
   struct has_RTTI
     {
-      using PlainType = typename remove_pointer<
-                        typename remove_reference<T>::type>::type;
-    
-      static constexpr bool value = std::is_polymorphic<PlainType>::value;
+      static constexpr bool value = std::is_polymorphic<PlainType<T>>::value;
     };
   
   template <typename SRC, typename TAR>
   struct can_downcast
     {
-      using PlainSRC = typename remove_pointer<
-                       typename remove_reference<SRC>::type>::type;
-      using PlainTAR = typename remove_pointer<
-                       typename remove_reference<TAR>::type>::type;
-    
-      static constexpr bool value = std::is_base_of<PlainSRC, PlainTAR>::value;
+      static constexpr bool value = std::is_base_of<PlainType<SRC>, PlainType<TAR>>::value;
     };
   
   template <typename SRC, typename TAR>
@@ -88,6 +85,20 @@ namespace util {
     : std::is_convertible<SRC,TAR>
     { };
   
+  template <typename SRC, typename TAR>
+  struct can_take_address
+    {
+      static constexpr bool value =  !std::is_pointer<typename remove_reference<SRC>::type>::value
+                                   && std::is_pointer<typename remove_reference<TAR>::type>::value;
+    };
+  
+  template <typename SRC, typename TAR>
+  struct can_dereference
+    {
+      static constexpr bool value =  !std::is_pointer<typename remove_reference<TAR>::type>::value
+                                   && std::is_pointer<typename remove_reference<SRC>::type>::value;
+    };
+  
   
   template <typename SRC, typename TAR>
   struct if_can_use_dynamic_downcast
@@ -98,6 +109,16 @@ namespace util {
   struct if_can_use_conversion
     : std::enable_if< can_use_conversion<SRC,TAR>::value, TAR>
     { };
+  
+  template <typename SRC, typename TAR>
+  struct if_can_take_address
+    : std::enable_if< can_take_address<SRC,TAR>::value, TAR>
+    { };
+  
+  template <typename SRC, typename TAR>
+  struct if_can_dereference
+    : std::enable_if< can_dereference<SRC,TAR>::value, TAR>
+    { };
     
   
       
@@ -121,6 +142,26 @@ namespace util {
           std::cerr << "convert-"<<lib::test::showRefKind<SRC>()<<" && ->"<<lib::test::showRefKind<SRC&&>()<<std::endl;
           return std::forward<SRC> (elem);
         }
+      
+      template<typename SRC>
+      static  typename if_can_take_address<SRC&&,TAR>::type
+      access (SRC&& elem)
+        {
+          std::cerr << "address-"<<lib::test::showRefKind<SRC>()<<" && ->"<<lib::test::showRefKind<SRC&&>()<<std::endl;
+          return AccessCasted<TAR>::access (&elem);
+        }
+      
+      template<typename SRC>
+      static  typename if_can_dereference<SRC&&,TAR>::type
+      access (SRC&& elem)
+        {
+          std::cerr << "deref-"<<lib::test::showRefKind<SRC>()<<" && ->"<<lib::test::showRefKind<SRC&&>()<<std::endl;
+          if (!elem)
+            throw error::Invalid("AccessCasted: attempt to build a value or reference from a NULL pointer"
+                                ,error::LUMIERA_ERROR_BOTTOM_VALUE);
+          
+          return AccessCasted<TAR>::access (*elem);
+        }
     };
   
   
diff --git a/tests/library/meta/access-casted-test.cpp b/tests/library/meta/access-casted-test.cpp
index d1b4be725..931c52706 100644
--- a/tests/library/meta/access-casted-test.cpp
+++ b/tests/library/meta/access-casted-test.cpp
@@ -34,6 +34,9 @@ using std::move;
 using std::string;
 using std::ostream;
 using std::cout;
+using std::endl;
+
+using lumiera::error::LUMIERA_ERROR_BOTTOM_VALUE;
 
 
 namespace util {
@@ -94,61 +97,77 @@ namespace test {
           E* pE = &f;
           D* pDE = pE;
           
-          cout <<  "can_downcast<B,D>     = " << can_downcast<B,D>::value << "\n";
-          cout <<  "can_downcast<B*,D*>   = " << can_downcast<B*,D*>::value << "\n";
-          cout <<  "can_downcast<B&,D&>   = " << can_downcast<B&,D&>::value << "\n";
-          cout <<  "can_downcast<B&,D*>   = " << can_downcast<B&,D*>::value << "\n";
-          cout <<  "can_downcast<B*,D&>   = " << can_downcast<B*,D&>::value << "\n";
-          cout <<  "can_downcast<B*&,D*&> = " << can_downcast<B*&,D*&>::value << "\n";
-          cout <<  "can_downcast<D*&,D*&> = " << can_downcast<D*&,D*&>::value << "\n";
+          cout <<  "can_downcast<B,D>     = " << can_downcast<B,D>::value <<endl;
+          cout <<  "can_downcast<B*,D*>   = " << can_downcast<B*,D*>::value <<endl;
+          cout <<  "can_downcast<B&,D&>   = " << can_downcast<B&,D&>::value <<endl;
+          cout <<  "can_downcast<B&,D*>   = " << can_downcast<B&,D*>::value <<endl;
+          cout <<  "can_downcast<B*,D&>   = " << can_downcast<B*,D&>::value <<endl;
+          cout <<  "can_downcast<B*&,D*&> = " << can_downcast<B*&,D*&>::value <<endl;
+          cout <<  "can_downcast<D*&,D*&> = " << can_downcast<D*&,D*&>::value <<endl;
           
-          cout <<  "can_downcast<D*,E*>   = " << can_downcast<D*,E*>::value << "\n";
-          cout <<  "can_downcast<E*,F*>   = " << can_downcast<E*,F*>::value << "\n";
+          cout <<  "can_downcast<D*,E*>   = " << can_downcast<D*,E*>::value <<endl;
+          cout <<  "can_downcast<E*,F*>   = " << can_downcast<E*,F*>::value <<endl;
           
-          cout <<  "has_RTTI<D*> = " << has_RTTI<D*>::value << "\n";
-          cout <<  "has_RTTI<E*> = " << has_RTTI<E*>::value << "\n";
-          cout <<  "has_RTTI<F*> = " << has_RTTI<F*>::value << "\n";
+          cout <<  "has_RTTI<D*> = " << has_RTTI<D*>::value <<endl;
+          cout <<  "has_RTTI<E*> = " << has_RTTI<E*>::value <<endl;
+          cout <<  "has_RTTI<F*> = " << has_RTTI<F*>::value <<endl;
           
-          cout <<  "is_convertible<D,D&>  = " << std::is_convertible<D,D&>::value << "\n";
-          cout <<  "is_convertible<D&,D>  = " << std::is_convertible<D&,D>::value << "\n";
+          cout <<  "is_convertible<D,D&>  = " << std::is_convertible<D,D&>::value <<endl;
+          cout <<  "is_convertible<D&,D>  = " << std::is_convertible<D&,D>::value <<endl;
           
           
-          cout <<  "can_use_dynamic_downcast<D,D&>  = " << can_use_dynamic_downcast<D,D&>::value << "\n";
-          cout <<  "can_use_conversion<D,D&>        = " << can_use_conversion<D,D&>::value << "\n";
-          cout <<  "can_use_dynamic_downcast<B*,D*> = " << can_use_dynamic_downcast<B*,D*>::value << "\n";
-          cout <<  "can_use_conversion<D*,B*>       = " << can_use_conversion<D*,B*>::value << "\n";
+          cout <<  "can_use_dynamic_downcast<D,D&>  = " << can_use_dynamic_downcast<D,D&>::value <<endl;
+          cout <<  "can_use_conversion<D,D&>        = " << can_use_conversion<D,D&>::value <<endl;
+          cout <<  "can_use_dynamic_downcast<B*,D*> = " << can_use_dynamic_downcast<B*,D*>::value <<endl;
+          cout <<  "can_use_conversion<D*,B*>       = " << can_use_conversion<D*,B*>::value <<endl;
           
-          cout <<  "can_use_dynamic_downcast<D*&,D*&> = " << can_use_dynamic_downcast<D*&,D*&>::value << "\n";
-          cout <<  "can_use_conversion<D*&,D*&>       = " << can_use_conversion<D*&,D*&>::value << "\n";
-          cout <<  "can_use_conversion<D*,E*>         = " << can_use_conversion<D*,E*>::value << "\n";
-          cout <<  "can_use_dynamic_downcast<D*&,E*>  = " << can_use_dynamic_downcast<D*&,E*>::value << "\n";
+          cout <<  "can_use_dynamic_downcast<D*&,D*&> = " << can_use_dynamic_downcast<D*&,D*&>::value <<endl;
+          cout <<  "can_use_conversion<D*&,D*&>       = " << can_use_conversion<D*&,D*&>::value <<endl;
+          cout <<  "can_use_conversion<D*,E*>         = " << can_use_conversion<D*,E*>::value <<endl;
+          cout <<  "can_use_dynamic_downcast<D*&,E*>  = " << can_use_dynamic_downcast<D*&,E*>::value <<endl;
           
+          cout <<  "=== standard case: References ==="<<endl;
+          cout <<  "Access(D  as D&)    --->" << AccessCasted<D&>::access(d)  <<endl;
+          cout <<  "Access(D& as D&)    --->" << AccessCasted<D&>::access(rD) <<endl;
           
-          cout <<  "Access(D  as D&)    --->" << AccessCasted<D&>::access(d)  << "\n";
-          cout <<  "Access(D& as D&)    --->" << AccessCasted<D&>::access(rD) << "\n";
-          cout <<  "Access(D  as D)     --->" << AccessCasted<D>::access(d) << "\n";
-          cout <<  "Access(D& as D)     --->" << AccessCasted<D>::access(rD) << "\n";
+          cout <<  "=== build a value object ==="<<endl;
+          cout <<  "Access(D  as D)     --->" << AccessCasted<D>::access(d) <<endl;
+          cout <<  "Access(D& as D)     --->" << AccessCasted<D>::access(rD) <<endl;
           D dd1(d);
-          cout <<  "Access(D&& as D)    --->" << AccessCasted<D>::access(move(dd1)) << "\n";
-//        cout <<  "Access(B& as D&)    --->" << AccessCasted<D&>::access(rB) << "\n";
-//        cout <<  "Access(D* as D*)    --->" << AccessCasted<D*>::access(pD) << "\n";
-//        cout <<  "Access(B* as D*)    --->" << AccessCasted<D*>::access(pB) << "\n";
-//        cout <<  "Access(D*& as D*&)  --->" << AccessCasted<D*&>::access(rpD) << "\n";
-//        cout <<  "Access(B*& as D*&)  --->" << AccessCasted<D*&>::access(rpB) << "\n";
+          cout <<  "Access(D&& as D)    --->" << AccessCasted<D>::access(move(dd1)) <<endl;
+          
+          cout <<  "=== take a pointer ==="<<endl;
+          cout <<  "Access(D  as D*)    --->" << AccessCasted<D*>::access(d)  <<endl;
+          cout <<  "Access(D& as D*)    --->" << AccessCasted<D*>::access(rD) <<endl;
+          
+          cout <<  "=== dereference a pointer ==="<<endl;
+          cout <<  "Access(D* as D&)    --->" << AccessCasted<D&>::access(pD)  <<endl;
+          cout <<  "Access(D* as D)     --->" << AccessCasted<D>::access(pD)  <<endl;
+          D* pdd1(pD);
+          cout <<  "Access(D*&& as D)   --->" << AccessCasted<D>::access(move(pdd1))  <<endl;
+          D* pNull(0);
+          VERIFY_ERROR(BOTTOM_VALUE, AccessCasted<D>::access(pNull));
+          
+          cout <<  "=== work cases: actual conversions ==="<<endl;
+//        cout <<  "Access(B& as D&)    --->" << AccessCasted<D&>::access(rB) <<endl;
+//        cout <<  "Access(D* as D*)    --->" << AccessCasted<D*>::access(pD) <<endl;
+//        cout <<  "Access(B* as D*)    --->" << AccessCasted<D*>::access(pB) <<endl;
+//        cout <<  "Access(D*& as D*&)  --->" << AccessCasted<D*&>::access(rpD) <<endl;
+//        cout <<  "Access(B*& as D*&)  --->" << AccessCasted<D*&>::access(rpB) <<endl;
 //        
-//        cout <<  "Access(D  as B&)    --->" << AccessCasted<B&>::access(d)  << "\n";
-//        cout <<  "Access(D& as B&)    --->" << AccessCasted<B&>::access(rD) << "\n";
-//        cout <<  "Access(B& as B&)    --->" << AccessCasted<D&>::access(rB) << "\n";
-//        cout <<  "Access(D* as B*)    --->" << AccessCasted<B*>::access(pD) << "\n";
-//        cout <<  "Access(B* as B*)    --->" << AccessCasted<B*>::access(pB) << "\n";
-//        cout <<  "Access(D*& as B*&)  --->" << AccessCasted<B*&>::access(rpD) << "\n";
-//        cout <<  "Access(B*& as B*&)  --->" << AccessCasted<B*&>::access(rpB) << "\n";
+//        cout <<  "Access(D  as B&)    --->" << AccessCasted<B&>::access(d)  <<endl;
+//        cout <<  "Access(D& as B&)    --->" << AccessCasted<B&>::access(rD) <<endl;
+//        cout <<  "Access(B& as B&)    --->" << AccessCasted<D&>::access(rB) <<endl;
+//        cout <<  "Access(D* as B*)    --->" << AccessCasted<B*>::access(pD) <<endl;
+//        cout <<  "Access(B* as B*)    --->" << AccessCasted<B*>::access(pB) <<endl;
+//        cout <<  "Access(D*& as B*&)  --->" << AccessCasted<B*&>::access(rpD) <<endl;
+//        cout <<  "Access(B*& as B*&)  --->" << AccessCasted<B*&>::access(rpB) <<endl;
 //        
-//        cout <<  "Access(D  as E&)    --->" << AccessCasted<E&>::access(d) << "\n";
-//        cout <<  "Access(E& as F&)    --->" << AccessCasted<F&>::access(rE) << "\n";
-//        cout <<  "Access(D(E)* as E*) --->" << AccessCasted<E*>::access(pDE) << "\n";
-//        cout <<  "Access(D(E)* as F*) --->" << AccessCasted<F*>::access(pDE) << "\n";
-//        cout <<  "Access(E* as F*)    --->" << AccessCasted<F*>::access(pE) << "\n";
+//        cout <<  "Access(D  as E&)    --->" << AccessCasted<E&>::access(d) <<endl;
+//        cout <<  "Access(E& as F&)    --->" << AccessCasted<F&>::access(rE) <<endl;
+//        cout <<  "Access(D(E)* as E*) --->" << AccessCasted<E*>::access(pDE) <<endl;
+//        cout <<  "Access(D(E)* as F*) --->" << AccessCasted<F*>::access(pDE) <<endl;
+//        cout <<  "Access(E* as F*)    --->" << AccessCasted<F*>::access(pE) <<endl;
         }
     };