clang fails to compile topologyfactory.hh
clang (ubunutu:16.4,debian:9) fails with the following errors
/duneci/modules/dune-geometry/dune/geometry/topologyfactory.hh:133:15: error: member reference base type 'Object *' (aka 'const typename Factory::Object *') is not a structure or union
object.reset( Factory::create( gt, key ) );
~~~~~~^~~~~~
/duneci/modules/dune-geometry/dune/geometry/topologyfactory.hh:134:20: error: member reference base type 'Object *' (aka 'const typename Factory::Object *') is not a structure or union
return object.get();
~~~~~~^~~~