[boundaryinfo] derive from base in bindings

dune/xt/grid/bindings.cc

@@ -32,6 +32,8 @@ struct for_Grid_and_Intersection
   static void addbind(py::module& m, const std::string& grid_id, const std::string& id)
   {
     using namespace Dune::XT::Grid;
+    pybind11::class_<BoundaryInfo<I>>(
+        m, std::string("BoundaryInfo__" + grid_id + id).c_str(), std::string("BoundaryInfo__" + grid_id + id).c_str());
     bind_BoundaryInfo<AllDirichletBoundaryInfo<I>>(m, "AllDirichletBoundaryInfo__" + grid_id + id);
     bind_BoundaryInfo<AllNeumannBoundaryInfo<I>>(m, "AllNeumannBoundaryInfo__" + grid_id + id);
     bind_BoundaryInfo<NormalBasedBoundaryInfo<I>>(m, "NormalBasedBoundaryInfo__" + grid_id + id);

dune/xt/grid/boundaryinfo.pbh

@@ -31,7 +31,7 @@ pybind11::class_<C> bind_BoundaryInfo(pybind11::module& m, const std::string& id
   namespace py = pybind11;
   using namespace pybind11::literals;
 
-  py::class_<C> c(m, id.c_str(), id.c_str(), py::metaclass());
+  py::class_<C, BoundaryInfo<typename C::IntersectionType>> c(m, id.c_str(), id.c_str(), py::metaclass());
 
   c.def(py::init<>());