Implement a shim that makes a scalar dune-functions basis look like a GridFunctionSpace
Usage example:
using Basis = Functions::PQkNodalBasis<GridView,1>; Basis basis(gridView);
typedef PDELab::DuneFunctionsGridFunctionSpace<Basis,Constraints,VectorBackend> GridFunctionSpace; GridFunctionSpace gfs(basis,constraints);
This is a step towards using the dune-functions bases in dune-pdelab. It currently only works for scalar bases, but I think it is still very useful: You don't have to explain to people what a FiniteElementMap is anymore. Also, bold people may be able to extend this to more general bases.
Is it possible to get such a wrapper merged in principle? If yes, then please have a look at the code: I am still no pdelab expert. I will then also provide a unit test.