dune-subgrid deprecation warning
On 2.7, if subgrid is installed, every test using a gridmanager will write the deprecation warning:
dune-common/dune/common/parallel/collectivecommunication.hh:2:2: warning: #warning "Deprecated header, use #include <dune/common/parallel/communication.hh> instead!" [-Wcpp]
#warning "Deprecated header, use #include <dune/common/parallel/communication.hh> instead!"
@kweis has already addressed this in a MR within dune-subgrid: dune-subgrid!16
This fix only works if c++17 is required, which it doesn't seem to be for dune-subgrid.
Would it make sense to take the changes made on dune-subgrid!16 and add it as a patch for releases/3.2?