message: Add an error message when used on periodic meshes.
diff: @@ -637,6 +637,7 @@ static void InitCeedTensorBasis(const FiniteElementSpace &fes,
  MFEM_VERIFY(tfe, "invalid FE");
  const FiniteElement *fe1d =
  fes.FEColl()->FiniteElementForGeometry(Geometry::SEGMENT);
  + MFEM_VERIFY(fe1d, "Periodic meshes not yet handled.");
  DenseMatrix shape1d(fe1d->GetDof(), ir.GetNPoints());
  DenseMatrix grad1d(fe1d->GetDof(), ir.GetNPoints());
  Vector qref1d(ir.GetNPoints()), qweight1d(ir.GetNPoints());
  