Workaround for LWG 2408: SFINAE-friendly std::iterator_traits.

Now available for GCC(libstdc++v3) < 4.5 and MSVC 12.0.
It means, there is no ambiguous about calling next/prior/... via ADL.

include/boost/fusion/view/filter_view/filter_view_iterator.hpp

@@ -67,6 +67,15 @@ namespace boost { namespace fusion
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename Category, typename First, typename Last, typename Pred>
+    struct iterator_traits< ::boost::fusion::filter_iterator<Category, First, Last, Pred> >
+    { };
+}
+#endif
+
 #endif
 
 

include/boost/fusion/view/flatten_view/flatten_view_iterator.hpp

@@ -194,6 +194,15 @@ namespace boost { namespace fusion { namespace extension
     };
 }}}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename First, typename Base>
+    struct iterator_traits< ::boost::fusion::flatten_view_iterator<First, Base> >
+    { };
+}
+#endif
+
 
 #endif
 

include/boost/fusion/view/joint_view/joint_view_iterator.hpp

@@ -56,6 +56,15 @@ namespace boost { namespace fusion
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename Category, typename First, typename Last, typename Concat>
+    struct iterator_traits< ::boost::fusion::joint_view_iterator<Category, First, Last, Concat> >
+    { };
+}
+#endif
+
 #endif
 
 

include/boost/fusion/view/nview/nview_iterator.hpp

@@ -54,6 +54,15 @@ namespace boost { namespace fusion
 
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename Sequence, typename Pos>
+    struct iterator_traits< ::boost::fusion::nview_iterator<Sequence, Pos> >
+    { };
+}
+#endif
+
 #endif
 
 

include/boost/fusion/view/repetitive_view/repetitive_view_iterator.hpp

@@ -53,5 +53,14 @@ namespace boost { namespace fusion
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename Sequence, typename Pos>
+    struct iterator_traits< ::boost::fusion::repetitive_view_iterator<Sequence, Pos> >
+    { };
+}
+#endif
+
 #endif
 

include/boost/fusion/view/reverse_view/reverse_view_iterator.hpp

@@ -54,5 +54,14 @@ namespace boost { namespace fusion
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename First>
+    struct iterator_traits< ::boost::fusion::reverse_view_iterator<First> >
+    { };
+}
+#endif
+
 #endif
 

include/boost/fusion/view/single_view/single_view_iterator.hpp

@@ -50,6 +50,15 @@ namespace boost { namespace fusion
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename SingleView, typename Pos>
+    struct iterator_traits< ::boost::fusion::single_view_iterator<SingleView, Pos> >
+    { };
+}
+#endif
+
 #if defined (BOOST_MSVC)
 #  pragma warning(pop)
 #endif

include/boost/fusion/view/transform_view/transform_view_iterator.hpp

@@ -76,5 +76,17 @@ namespace boost { namespace fusion
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename First, typename F>
+    struct iterator_traits< ::boost::fusion::transform_view_iterator<First, F> >
+    { };
+    template <typename First1, typename First2, typename F>
+    struct iterator_traits< ::boost::fusion::transform_view_iterator2<First1, First2, F> >
+    { };
+}
+#endif
+
 #endif
 

include/boost/fusion/view/zip_view/zip_view_iterator.hpp

@@ -46,4 +46,13 @@ namespace boost { namespace fusion {
     };
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename IteratorSequence, typename Traversal>
+    struct iterator_traits< ::boost::fusion::zip_view_iterator<IteratorSequence, Traversal> >
+    { };
+}
+#endif
+
 #endif