diff --git a/triqs/arrays/array.hpp b/triqs/arrays/array.hpp
index d3ff72b9..2791be27 100644
--- a/triqs/arrays/array.hpp
+++ b/triqs/arrays/array.hpp
@@ -20,7 +20,7 @@
  ******************************************************************************/
 #ifndef TRIQS_ARRAYS_ARRAY_H
 #define TRIQS_ARRAYS_ARRAY_H
-#include<triqs/utility/first_include.hpp>
+#include <triqs/utility/first_include.hpp>
 #include "indexmaps/cuboid/map.hpp"
 #include "indexmaps/cuboid/slice.hpp"
 #include "impl/indexmap_storage_pair.hpp"
@@ -45,7 +45,6 @@ namespace triqs { namespace arrays {
    typedef array     <ValueType,Rank,Opt,TraversalOrder>       regular_type;
    typedef array_view<ValueType,Rank,Opt,TraversalOrder>       view_type;
    typedef array_view<ValueType,Rank,Opt,TraversalOrder,true>  weak_view_type;
-   typedef void has_view_type_tag;
  
    /// Build from an IndexMap and a storage 
    template<typename S> array_view (indexmap_type const & Ind,S const & Mem): IMPL_TYPE(Ind, Mem) {}
@@ -101,7 +100,6 @@ namespace triqs { namespace arrays {
     typedef array     <ValueType,Rank,Opt,TraversalOrder>      regular_type;
     typedef array_view<ValueType,Rank,Opt,TraversalOrder>      view_type;
     typedef array_view<ValueType,Rank,Opt,TraversalOrder,true> weak_view_type;
-    typedef void has_view_type_tag; 
 
     /// Empty array.
     explicit array(memory_layout<Rank> ml = memory_layout<Rank>(IMPL_TYPE::indexmap_type::traversal_order)) :IMPL_TYPE(ml){} 
diff --git a/triqs/arrays/matrix.hpp b/triqs/arrays/matrix.hpp
index 18a983da..a1819165 100644
--- a/triqs/arrays/matrix.hpp
+++ b/triqs/arrays/matrix.hpp
@@ -54,7 +54,6 @@ namespace triqs { namespace arrays {
     typedef matrix     <ValueType,Opt,TraversalOrder>       regular_type;
     typedef matrix_view<ValueType,Opt,TraversalOrder>       view_type;
     typedef matrix_view<ValueType,Opt,TraversalOrder,true>  weak_view_type;
-    typedef void has_view_type_tag;
 
     typedef typename IMPL_TYPE::indexmap_type indexmap_type;
     typedef typename IMPL_TYPE::storage_type storage_type;
@@ -116,7 +115,6 @@ namespace triqs { namespace arrays {
     typedef matrix     <ValueType,Opt,TraversalOrder>      regular_type;
     typedef matrix_view<ValueType,Opt,TraversalOrder>      view_type;
     typedef matrix_view<ValueType,Opt,TraversalOrder,true> weak_view_type;
-    typedef void has_view_type_tag;
 
     /// Empty matrix.
     matrix(memory_layout<2> ml = memory_layout<2>(IMPL_TYPE::indexmap_type::traversal_order) ):  IMPL_TYPE(indexmap_type(ml)) {}
diff --git a/triqs/arrays/vector.hpp b/triqs/arrays/vector.hpp
index 960bf365..8fcc482e 100644
--- a/triqs/arrays/vector.hpp
+++ b/triqs/arrays/vector.hpp
@@ -43,7 +43,6 @@ namespace triqs { namespace arrays {
    typedef vector     <ValueType,Opt>       regular_type;
    typedef vector_view<ValueType,Opt,false> view_type;
    typedef vector_view<ValueType,Opt,true>  weak_view_type;
-   typedef void has_view_type_tag;
 
    typedef typename IMPL_TYPE::indexmap_type indexmap_type;
    typedef typename IMPL_TYPE::storage_type storage_type;
@@ -110,7 +109,6 @@ namespace triqs { namespace arrays {
     typedef vector     <ValueType,Opt>      regular_type;
     typedef vector_view<ValueType,Opt>      view_type;
     typedef vector_view<ValueType,Opt,true> weak_view_type;
-    typedef void has_view_type_tag;
 
     /// Empty vector.
     vector(){}
diff --git a/triqs/gfs/local/tail.hpp b/triqs/gfs/local/tail.hpp
index d0c34254..8cdbebcd 100644
--- a/triqs/gfs/local/tail.hpp
+++ b/triqs/gfs/local/tail.hpp
@@ -50,7 +50,6 @@ namespace triqs { namespace gfs { namespace local {
  /// A common implementation class. Idiom : ValueView
  template<bool IsView> class tail_impl  {
   public :
-   typedef void has_view_type_tag; // Idiom : ValueView
    typedef tail_view view_type;
    typedef tail      regular_type;
 
diff --git a/triqs/gfs/tools.hpp b/triqs/gfs/tools.hpp
index a9d0ebe8..5c2eddb3 100644
--- a/triqs/gfs/tools.hpp
+++ b/triqs/gfs/tools.hpp
@@ -74,7 +74,6 @@ namespace triqs { namespace gfs {
  struct nothing {
   template<typename... Args> explicit nothing(Args...) {} // takes anything, do nothing..
   nothing() {}
-  typedef void has_view_type_tag;     // Idiom : ValueView  
   typedef nothing view_type;
   typedef nothing regular_type;
   void rebind (nothing){}
diff --git a/triqs/utility/draft/value_view.hpp b/triqs/utility/draft/value_view.hpp
index 129058ed..218e1f32 100644
--- a/triqs/utility/draft/value_view.hpp
+++ b/triqs/utility/draft/value_view.hpp
@@ -35,7 +35,6 @@ namespace triqs {
   friend class value_view<T,false>;
 
   public:
-  typedef void has_view_type_tag; // Idiom : ValueView 
   typedef value_view<T,true>  view_type;
   typedef value_view<T,false> regular_type;
   typedef typename std::remove_cv<typename std::remove_reference <T>::type >::type value_type;
@@ -66,7 +65,6 @@ namespace triqs {
   std::shared_ptr<T> p;
   friend class value_view<T,true>;
   public:
-  typedef void has_view_type_tag; // Idiom : ValueView 
   typedef value_view<T,true>  view_type;
   typedef value_view<T,false> regular_type;
   typedef typename std::remove_cv<typename std::remove_reference <T>::type >::type value_type;
diff --git a/triqs/utility/view_tools.hpp b/triqs/utility/view_tools.hpp
index 62b66c8e..39cc796c 100644
--- a/triqs/utility/view_tools.hpp
+++ b/triqs/utility/view_tools.hpp
@@ -24,10 +24,6 @@
 
 namespace triqs {
 
-// keep old solution for a while to check portability and then remove tag
-#define TRIQS_DETECT_VIEWS
-#ifdef TRIQS_DETECT_VIEWS
-
  template<typename T> void nop(T ...){};
  template<typename T, typename Enable=void> struct has_view : std::false_type {};
  template<typename T> struct has_view<T, decltype(nop(std::declval<typename T::view_type>(),std::declval<typename T::regular_type>()))> : std::true_type {};
@@ -43,28 +39,14 @@ namespace triqs {
  template<typename T, bool HasView = has_view<T>::value> struct const_view_type_if_exists_else_type;
  template<typename T> struct const_view_type_if_exists_else_type<T,false> {typedef T type;};
  template<typename T> struct const_view_type_if_exists_else_type<T,true>  {typedef const typename T::view_type type;};
- // template<typename T> struct const_view_type_if_exists_else_type<const T, typename T::has_view_type_tag> {typedef const typename T::view_type type;};
-
-#else
-
- template<typename T, typename Void =void> struct regular_type_if_exists_else_type {typedef T type;};
- template<typename T> struct regular_type_if_exists_else_type<T, typename T::has_view_type_tag> {typedef typename T::regular_type type;};
-
- template<typename T, typename Void =void> struct view_type_if_exists_else_type {typedef T type;};
- template<typename T> struct view_type_if_exists_else_type<T, typename T::has_view_type_tag> {typedef typename T::view_type type;};
-
- template<typename T, typename Void =void> struct const_view_type_if_exists_else_type {typedef T type;};
- template<typename T> struct const_view_type_if_exists_else_type<T, typename T::has_view_type_tag> {typedef const typename T::view_type type;};
- // template<typename T> struct const_view_type_if_exists_else_type<const T, typename T::has_view_type_tag> {typedef const typename T::view_type type;};
-
-#endif
 
+ /*
  // replacement of std::plus for views ...
  template <class T> struct add_views : std::binary_function <T,T,T> {
-  T operator() (const T& x, const T& y) const
-  { typename T::regular_type r(x); r =r + y; return r;}
+ T operator() (const T& x, const T& y) const
+ { typename T::regular_type r(x); r =r + y; return r;}
  };
-
+ */
 
 }//namespace triqs
 #endif