Properly deprecate make_array.hh

CHANGELOG.md

@@ -57,6 +57,10 @@
 - The deprecated compatibility header `optional.hh` is removed. Include
   `<optional>` instead.
 
+- The compatibility header `make_array.hh` is deprecated and will be
+  removed after Dune 2.8. Use deduction guide of `std::array` or
+  `std::to_array`.
+
 # Release 2.8
 
 - Set minimal required CMake version in cmake to >= 3.13.

dune/common/std/make_array.hh

@@ -8,6 +8,9 @@
 #include <experimental/array>
 #endif
 
+#warning make_array.hh is deprecated and will be removed after Dune 2.8. \
+  Use deduction guide of `std::array` or `std::to_array`.
+
 namespace Dune {
 namespace Std {
 

dune/common/test/arraytest.cc

@@ -10,6 +10,7 @@
 
 #include <dune/common/std/make_array.hh>
 #include <dune/common/classname.hh>
+#include <dune/common/deprecated.hh>
 #include <dune/common/fvector.hh>
 #include <dune/common/streamoperators.hh>
 
@@ -21,6 +22,8 @@ void f(const std::array<T, n> &a)
 }
 
 int main() {
+  DUNE_NO_DEPRECATED_BEGIN
+
   // check that make_array works
   f(Dune::Std::make_array(1, 2));
   f(Dune::Std::make_array(1, 2, 3));
@@ -34,4 +37,6 @@ int main() {
 
   Dune::FieldVector<double, 2> x(0);
   f(Dune::Std::make_array(x, x));
+
+  DUNE_NO_DEPRECATED_END
 }