make tuple_size and tuple_element a class

src/amdis/common/Range.hpp

@@ -57,12 +57,13 @@ namespace AMDiS
 namespace std
 {
   template <class Int, Int I0, Int I1>
-  struct tuple_size<AMDiS::Impl::range_impl<Int,I0,I1>>
-      : std::integral_constant<std::size_t, std::size_t(I1-I0)> {};
+  class tuple_size<AMDiS::Impl::range_impl<Int,I0,I1>>
+      : public std::integral_constant<std::size_t, std::size_t(I1-I0)> {};
 
   template <std::size_t I, class Int, Int I0, Int I1>
-  struct tuple_element<I,AMDiS::Impl::range_impl<Int,I0,I1>>
+  class tuple_element<I,AMDiS::Impl::range_impl<Int,I0,I1>>
   {
+  public:
     using type = Int;
   };