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/container/deque/deque_iterator.hpp

@@ -118,4 +118,13 @@ namespace boost { namespace fusion {
 
 }}
 
+#ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
+namespace std
+{
+    template <typename Seq, int Pos>
+    struct iterator_traits< ::boost::fusion::deque_iterator<Seq, Pos> >
+    { };
+}
+#endif
+
 #endif