avoid deprecation warnings when using Dune 2.6
Use the DUNE_VERSION*
macros to distinguish between Dune >= 2.6
and < 2.6. Employ the correspondingly correct types, constructors
and function calls for Mappers and ReferenceElements.
Use the DUNE_VERSION*
macros to distinguish between Dune >= 2.6
and < 2.6. Employ the correspondingly correct types, constructors
and function calls for Mappers and ReferenceElements.