Use DUNE_FORCE_INLINE instead of attribute always_inline

dune/common/test/foreachindex.hh

@@ -10,6 +10,7 @@
 #include <type_traits>
 #include <utility>
 
+#include <dune/common/forceinline.hh>
 #include <dune/common/std/extents.hh>
 #include <dune/common/std/span.hh>
 #include <dune/common/std/functional.hh>
@@ -18,8 +19,7 @@ namespace Dune {
 namespace Impl {
 
 template <class Extents, class Fun, class... Indices>
-inline __attribute__((always_inline))
-void forEachIndexImpl (const Extents& extents, Fun f, Indices... ii)
+DUNE_FORCE_INLINE void forEachIndexImpl (const Extents& extents, Fun f, Indices... ii)
 {
   constexpr typename Extents::rank_type pos = sizeof...(Indices);
   if constexpr(pos < Extents::rank()) {
@@ -43,8 +43,7 @@ void forEachIndexImpl (const Extents& extents, Fun f, Indices... ii)
 template <class Extents, class Fun,
   class I = std::array<typename Extents::index_type,Extents::rank()>,
   std::enable_if_t<std::is_invocable_v<Fun,I>, int> = 0>
-inline __attribute__((always_inline))
-void forEachIndex (const Extents& extents, Fun f)
+DUNE_FORCE_INLINE void forEachIndex (const Extents& extents, Fun f)
 {
   Impl::forEachIndexImpl(extents, std::move(f));
 }