Merge branch 'issue/remove_warning' into 'master'

replace is_indexable by IsIndexable

See merge request extensions/dune-vtk!20

dune/vtk/defaultvtkfunction.hh

@@ -67,7 +67,7 @@ namespace Dune
 
       // Evaluate a component of a vector valued data
       template <class T,
-        std::enable_if_t<Dune::is_indexable<T,int>::value, int> = 0>
+        std::enable_if_t<IsIndexable<T,int>::value, int> = 0>
       double evaluateImpl (int comp, T const& value) const
       {
         return value[comp];
@@ -75,7 +75,7 @@ namespace Dune
 
       // Return the scalar values
       template <class T,
-        std::enable_if_t<not Dune::is_indexable<T,int>::value, int> = 0>
+        std::enable_if_t<not IsIndexable<T,int>::value, int> = 0>
       double evaluateImpl (int comp, T const& value) const
       {
         assert(comp == 0);