diff --git a/include/boost/move/detail/meta_utils.hpp b/include/boost/move/detail/meta_utils.hpp
index a8a61db..323c13a 100644
--- a/include/boost/move/detail/meta_utils.hpp
+++ b/include/boost/move/detail/meta_utils.hpp
@@ -332,6 +332,11 @@ struct eval_if
     : if_<C,T1,T2>::type
 {};
 
+
+#if defined(BOOST_GCC) && (BOOST_GCC <= 40000)
+#define BOOST_MOVE_HELPERS_RETURN_SFINAE_BROKEN
+#endif
+
 template<class T, class U, class R = void>
 struct enable_if_convertible
    : enable_if< is_convertible<T, U>, R>
diff --git a/include/boost/move/detail/move_helpers.hpp b/include/boost/move/detail/move_helpers.hpp
index e3b8883..7b62e26 100644
--- a/include/boost/move/detail/move_helpers.hpp
+++ b/include/boost/move/detail/move_helpers.hpp
@@ -26,9 +26,9 @@
 #if defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
 
 #define BOOST_MOVE_CATCH_CONST(U)  \
-   typename ::boost::move_detail::if_< ::boost::move_detail::is_class_or_union<U>, BOOST_CATCH_CONST_RLVALUE(U), const U &>::type
+   typename ::boost::move_detail::if_< ::boost::move_detail::is_class<U>, BOOST_CATCH_CONST_RLVALUE(U), const U &>::type
 #define BOOST_MOVE_CATCH_RVALUE(U)\
-   typename ::boost::move_detail::if_< ::boost::move_detail::is_class_or_union<U>, BOOST_RV_REF(U), ::boost::move_detail::nat>::type
+   typename ::boost::move_detail::if_< ::boost::move_detail::is_class<U>, BOOST_RV_REF(U), ::boost::move_detail::nat>::type
 #define BOOST_MOVE_CATCH_FWD(U) BOOST_FWD_REF(U)
 #else
 #define BOOST_MOVE_CATCH_CONST(U)  const U &
@@ -36,142 +36,216 @@
 #define BOOST_MOVE_CATCH_FWD(U)    U &&
 #endif
 
-#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
-#define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
-   RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_CONST(TYPE) x)\
-   {  return FWD_FUNCTION(static_cast<const TYPE&>(x)); }\
-\
-   RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
-   {  return FWD_FUNCTION(::boost::move(x));  }\
-\
-   RETURN_VALUE PUB_FUNCTION(TYPE &x)\
-   {  return FWD_FUNCTION(const_cast<const TYPE &>(x)); }\
-\
-   template<class BOOST_MOVE_TEMPL_PARAM>\
-   typename ::boost::move_detail::enable_if_and\
-                     < RETURN_VALUE \
-                     , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
-                     , ::boost::move_detail::is_class_or_union<TYPE>\
-                     , ::boost::has_move_emulation_disabled<BOOST_MOVE_TEMPL_PARAM>\
-                     >::type\
-   PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u)\
-   { return FWD_FUNCTION(u); }\
-\
-   template<class BOOST_MOVE_TEMPL_PARAM>\
-   typename ::boost::move_detail::disable_if_or\
-                     < RETURN_VALUE \
-                     , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM> \
-                     , ::boost::move_detail::and_ \
-                        < ::boost::move_detail::is_rv<BOOST_MOVE_TEMPL_PARAM> \
-                        , ::boost::move_detail::is_class_or_union<BOOST_MOVE_TEMPL_PARAM> \
-                        > \
-                     >::type\
-   PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u)\
-   {\
-      TYPE t(u);\
-      return FWD_FUNCTION(::boost::move(t));\
-   }\
+////////////////////////////////////////
 //
+// BOOST_MOVE_CONVERSION_AWARE_CATCH
+//
+////////////////////////////////////////
+
+#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
+   #define BOOST_MOVE_CONVERSION_AWARE_CATCH_COMMON(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+      RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_CONST(TYPE) x)\
+      {  return FWD_FUNCTION(static_cast<const TYPE&>(x)); }\
+      \
+      RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
+      {  return FWD_FUNCTION(::boost::move(x));  }\
+      \
+      RETURN_VALUE PUB_FUNCTION(TYPE &x)\
+      {  return FWD_FUNCTION(const_cast<const TYPE &>(x)); }\
+   //
+   #if defined(BOOST_MOVE_HELPERS_RETURN_SFINAE_BROKEN)
+      #define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+         BOOST_MOVE_CONVERSION_AWARE_CATCH_COMMON(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         RETURN_VALUE PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u,\
+            typename ::boost::move_detail::enable_if_and\
+                                 < ::boost::move_detail::nat \
+                                 , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
+                                 , ::boost::move_detail::is_class<TYPE>\
+                                 , ::boost::has_move_emulation_disabled<BOOST_MOVE_TEMPL_PARAM>\
+                                 >::type* = 0)\
+         { return FWD_FUNCTION(u); }\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         RETURN_VALUE PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u,\
+            typename ::boost::move_detail::disable_if_or\
+                              < ::boost::move_detail::nat \
+                              , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM> \
+                              , ::boost::move_detail::and_ \
+                                 < ::boost::move_detail::is_rv<BOOST_MOVE_TEMPL_PARAM> \
+                                 , ::boost::move_detail::is_class<BOOST_MOVE_TEMPL_PARAM> \
+                                 > \
+                              >::type* = 0)\
+         {\
+            TYPE t(u);\
+            return FWD_FUNCTION(::boost::move(t));\
+         }\
+      //
+   #else
+      #define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+         BOOST_MOVE_CONVERSION_AWARE_CATCH_COMMON(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         typename ::boost::move_detail::enable_if_and\
+                                       < RETURN_VALUE \
+                                       , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
+                                       , ::boost::move_detail::is_class<TYPE>\
+                                       , ::boost::has_move_emulation_disabled<BOOST_MOVE_TEMPL_PARAM>\
+                                       >::type\
+            PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u)\
+         { return FWD_FUNCTION(u); }\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         typename ::boost::move_detail::disable_if_or\
+                           < RETURN_VALUE \
+                           , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM> \
+                           , ::boost::move_detail::and_ \
+                              < ::boost::move_detail::is_rv<BOOST_MOVE_TEMPL_PARAM> \
+                              , ::boost::move_detail::is_class<BOOST_MOVE_TEMPL_PARAM> \
+                              > \
+                           >::type\
+            PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u)\
+         {\
+            TYPE t(u);\
+            return FWD_FUNCTION(::boost::move(t));\
+         }\
+      //
+   #endif
+#elif (defined(_MSC_VER) && (_MSC_VER == 1600))
+
+   #define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+      RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_CONST(TYPE) x)\
+      {  return FWD_FUNCTION(static_cast<const TYPE&>(x)); }\
+      \
+      RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
+      {  return FWD_FUNCTION(::boost::move(x));  }\
+      \
+      template<class BOOST_MOVE_TEMPL_PARAM>\
+      typename ::boost::move_detail::enable_if_c\
+                        < !::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>::value\
+                        , RETURN_VALUE >::type\
+      PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u)\
+      {\
+         TYPE t(u);\
+         return FWD_FUNCTION(::boost::move(t));\
+      }\
+   //
+
+#else    //BOOST_NO_CXX11_RVALUE_REFERENCES
+
+   #define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
+      RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_CONST(TYPE) x)\
+      {  return FWD_FUNCTION(static_cast<const TYPE&>(x)); }\
+      \
+      RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
+      {  return FWD_FUNCTION(::boost::move(x));  }\
+   //
+
+#endif   //BOOST_NO_CXX11_RVALUE_REFERENCES
+
+////////////////////////////////////////
+//
+// BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG
+//
+////////////////////////////////////////
+
+#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
+   #define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG_COMMON(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_CONST(TYPE) x)\
+      {  return FWD_FUNCTION(arg1, static_cast<const TYPE&>(x)); }\
+      \
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
+      {  return FWD_FUNCTION(arg1, ::boost::move(x));  }\
+      \
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, TYPE &x)\
+      {  return FWD_FUNCTION(arg1, const_cast<const TYPE &>(x)); }\
+   //
+   #if defined(BOOST_MOVE_HELPERS_RETURN_SFINAE_BROKEN)
+      #define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+         BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG_COMMON(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         RETURN_VALUE PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u,\
+            typename ::boost::move_detail::enable_if_and\
+                              < ::boost::move_detail::nat \
+                              , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
+                              , ::boost::has_move_emulation_disabled<BOOST_MOVE_TEMPL_PARAM>\
+                              >::type* = 0)\
+         { return FWD_FUNCTION(arg1, u); }\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         RETURN_VALUE PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u,\
+            typename ::boost::move_detail::disable_if_or\
+                              < void \
+                              , ::boost::move_detail::is_rv<BOOST_MOVE_TEMPL_PARAM>\
+                              , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
+                              , ::boost::move_detail::is_convertible<BOOST_MOVE_TEMPL_PARAM, UNLESS_CONVERTIBLE_TO>\
+                              >::type* = 0)\
+         {\
+            TYPE t(u);\
+            return FWD_FUNCTION(arg1, ::boost::move(t));\
+         }\
+      //
+   #else
+      #define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+         BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG_COMMON(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         typename ::boost::move_detail::enable_if_and\
+                           < RETURN_VALUE \
+                           , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
+                           , ::boost::has_move_emulation_disabled<BOOST_MOVE_TEMPL_PARAM>\
+                           >::type\
+            PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u)\
+         { return FWD_FUNCTION(arg1, u); }\
+         \
+         template<class BOOST_MOVE_TEMPL_PARAM>\
+         typename ::boost::move_detail::disable_if_or\
+                           < RETURN_VALUE \
+                           , ::boost::move_detail::is_rv<BOOST_MOVE_TEMPL_PARAM>\
+                           , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
+                           , ::boost::move_detail::is_convertible<BOOST_MOVE_TEMPL_PARAM, UNLESS_CONVERTIBLE_TO>\
+                           >::type\
+            PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u)\
+         {\
+            TYPE t(u);\
+            return FWD_FUNCTION(arg1, ::boost::move(t));\
+         }\
+      //
+   #endif
 
 #elif (defined(_MSC_VER) && (_MSC_VER == 1600))
 
-#define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
-   RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_CONST(TYPE) x)\
-   {  return FWD_FUNCTION(static_cast<const TYPE&>(x)); }\
-\
-   RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
-   {  return FWD_FUNCTION(::boost::move(x));  }\
-\
-   template<class BOOST_MOVE_TEMPL_PARAM>\
-   typename ::boost::move_detail::enable_if_c\
-                     < !::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>::value\
-                     , RETURN_VALUE >::type\
-   PUB_FUNCTION(const BOOST_MOVE_TEMPL_PARAM &u)\
-   {\
-      TYPE t(u);\
-      return FWD_FUNCTION(::boost::move(t));\
-   }\
-//
+   #define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_CONST(TYPE) x)\
+      {  return FWD_FUNCTION(arg1, static_cast<const TYPE&>(x)); }\
+      \
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
+      {  return FWD_FUNCTION(arg1, ::boost::move(x));  }\
+      \
+      template<class BOOST_MOVE_TEMPL_PARAM>\
+      typename ::boost::move_detail::disable_if_or\
+                        < RETURN_VALUE \
+                        , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM> \
+                        , ::boost::move_detail::is_convertible<BOOST_MOVE_TEMPL_PARAM, UNLESS_CONVERTIBLE_TO> \
+                        >::type\
+      PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u)\
+      {\
+         TYPE t(u);\
+         return FWD_FUNCTION(arg1, ::boost::move(t));\
+      }\
+   //
 
 #else
 
-#define BOOST_MOVE_CONVERSION_AWARE_CATCH(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION)\
-   RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_CONST(TYPE) x)\
-   {  return FWD_FUNCTION(static_cast<const TYPE&>(x)); }\
-\
-   RETURN_VALUE PUB_FUNCTION(BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
-   {  return FWD_FUNCTION(::boost::move(x));  }\
-//
-
-#endif
-
-
-#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
-
-#define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_CONST(TYPE) x)\
-   {  return FWD_FUNCTION(arg1, static_cast<const TYPE&>(x)); }\
-\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
-   {  return FWD_FUNCTION(arg1, ::boost::move(x));  }\
-\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, TYPE &x)\
-   {  return FWD_FUNCTION(arg1, const_cast<const TYPE &>(x)); }\
-\
-   template<class BOOST_MOVE_TEMPL_PARAM>\
-   typename ::boost::move_detail::enable_if_and\
-                     < RETURN_VALUE \
-                     , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
-                     , ::boost::has_move_emulation_disabled<BOOST_MOVE_TEMPL_PARAM>\
-                     >::type\
-   PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u)\
-   { return FWD_FUNCTION(arg1, u); }\
-\
-   template<class BOOST_MOVE_TEMPL_PARAM>\
-   typename ::boost::move_detail::disable_if_or\
-                     < RETURN_VALUE \
-                     , ::boost::move_detail::is_rv<BOOST_MOVE_TEMPL_PARAM>\
-                     , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM>\
-                     , ::boost::move_detail::is_convertible<BOOST_MOVE_TEMPL_PARAM, UNLESS_CONVERTIBLE_TO>\
-                     >::type\
-   PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u)\
-   {\
-      TYPE t(u);\
-      return FWD_FUNCTION(arg1, ::boost::move(t));\
-   }\
-//
-
-#elif (defined(_MSC_VER) && (_MSC_VER == 1600))
-
-#define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_CONST(TYPE) x)\
-   {  return FWD_FUNCTION(arg1, static_cast<const TYPE&>(x)); }\
-\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
-   {  return FWD_FUNCTION(arg1, ::boost::move(x));  }\
-\
-   template<class BOOST_MOVE_TEMPL_PARAM>\
-   typename ::boost::move_detail::disable_if_or\
-                     < RETURN_VALUE \
-                     , ::boost::move_detail::is_same<TYPE, BOOST_MOVE_TEMPL_PARAM> \
-                     , ::boost::move_detail::is_convertible<BOOST_MOVE_TEMPL_PARAM, UNLESS_CONVERTIBLE_TO> \
-                     >::type\
-   PUB_FUNCTION(ARG1 arg1, const BOOST_MOVE_TEMPL_PARAM &u)\
-   {\
-      TYPE t(u);\
-      return FWD_FUNCTION(arg1, ::boost::move(t));\
-   }\
-//
-
-#else
-
-#define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_CONST(TYPE) x)\
-   {  return FWD_FUNCTION(arg1, static_cast<const TYPE&>(x)); }\
-\
-   RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
-   {  return FWD_FUNCTION(arg1, ::boost::move(x));  }\
-//
+   #define BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(PUB_FUNCTION, TYPE, RETURN_VALUE, FWD_FUNCTION, ARG1, UNLESS_CONVERTIBLE_TO)\
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_CONST(TYPE) x)\
+      {  return FWD_FUNCTION(arg1, static_cast<const TYPE&>(x)); }\
+      \
+      RETURN_VALUE PUB_FUNCTION(ARG1 arg1, BOOST_MOVE_CATCH_RVALUE(TYPE) x) \
+      {  return FWD_FUNCTION(arg1, ::boost::move(x));  }\
+   //
 
 #endif