diff --git a/include/boost/fusion/container/vector/vector.hpp b/include/boost/fusion/container/vector/vector.hpp
index f20e1de0..abe2d7bb 100644
--- a/include/boost/fusion/container/vector/vector.hpp
+++ b/include/boost/fusion/container/vector/vector.hpp
@@ -168,15 +168,9 @@ namespace boost { namespace fusion
                 : elem(std::forward<U>(rhs))
             {}
 
-            using elem_type = T;
             T elem;
         };
 
-        // placed outside of vector_data due to GCC < 6 bug
-        template <std::size_t J, typename U>
-        static inline BOOST_FUSION_GPU_ENABLED
-        store<J, U> store_at_impl(store<J, U>*);
-
         template <typename I, typename ...T>
         struct vector_data;
 
@@ -228,23 +222,32 @@ namespace boost { namespace fusion
 #endif
             }
 
-        private:
-            template <std::size_t J>
-            using store_at = decltype(store_at_impl<J>(static_cast<vector_data*>(nullptr)));
+            template <std::size_t N, typename U>
+            static BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
+            U& at_detail(store<N, U>* this_)
+            {
+                return this_->elem;
+            }
+
+            template <std::size_t N, typename U>
+            static BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
+            U const& at_detail(store<N, U> const* this_)
+            {
+                return this_->elem;
+            }
 
-        public:
             template <typename J>
             BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
-            typename store_at<J::value>::elem_type& at_impl(J)
+            auto at_impl(J) -> decltype(at_detail<J::value>(&std::declval<vector_data&>()))
             {
-                return store_at<J::value>::elem;
+                return at_detail<J::value>(this);
             }
 
             template <typename J>
             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
-            typename store_at<J::value>::elem_type const& at_impl(J) const
+            auto at_impl(J) const -> decltype(at_detail<J::value>(&std::declval<vector_data const&>()))
             {
-                return store_at<J::value>::elem;
+                return at_detail<J::value>(this);
             }
         };
     } // namespace boost::fusion::vector_detail