Already the same on every version

From DOLFINx 0.10 on, these work the same way on 0.10, 0.11 and main, so fenicsx-compat has no wrapper for them. Call DOLFINx directly. Older code often still carries version branches for them, which can be deleted.

To	Call this on every version	Notes
Get the interpolation points of an element	V.element.interpolation_points	A property on the Python FiniteElement. Only the C++ object has the method V.element._cpp_object.interpolation_points().
Build a C++ function space	dolfinx.cpp.fem.FunctionSpace_float64(mesh._cpp_object, element._cpp_object, dofmap._cpp_object)	No value_shape argument. _float32 likewise.
Count the dofs in an entity’s closure	len(layout.entity_closure_dofs(dim, i))	ElementDofLayout.num_entity_closure_dofs and num_entity_dofs only exist in 0.10. entity_dofs and entity_closure_dofs exist everywhere.
Pack constants and coefficients	dolfinx.fem.pack_constants(form), dolfinx.fem.pack_coefficients(form)	Public in dolfinx.fem everywhere. No need for dolfinx.cpp.fem.pack_*(form._cpp_object).
Read gmsh models	dolfinx.io.gmsh	dolfinx.io.gmshio no longer exists. model_to_mesh returns a MeshData named tuple, so the mesh is .mesh. For the ghost mode, see model_to_mesh.
Find which process owns points	dolfinx.geometry.determine_point_ownership(mesh, points, padding=tol)	Returns a PointOwnershipData with src_owner, dest_owner, dest_points and dest_cells. padding has no default.
Compute integration entities	dolfinx.fem.compute_integration_domains(integral_type, mesh.topology, entities)	Three arguments, no dimension. Takes the Python topology. Returns a flat array.
Build a C++ topology	dolfinx.cpp.mesh.Topology(cell_type, vertex_map, cell_map, cells, original_index)	The only constructor; it takes no communicator. The index maps and cells must be C++ objects, see unwrap_index_map.
Create and assemble blocked or nested PETSc objects	dolfinx.fem.petsc.create_vector(spaces, kind=...), create_matrix(a, kind=...), assemble_vector(L, kind=...), assemble_matrix(a, bcs=...)	The *_block and *_nest functions are gone. kind="nest" gives a nest object; for one blocked object, kind="mpi" is used by scifem on 0.11 and main.

Differences with no wrapper

These do differ between versions, and fenicsx-compat does not cover them.

What	0.10, 0.11	main	Portable
Set Dirichlet values in an array	dolfinx.fem.set_bc(b, bcs, x0, alpha), deprecated in 0.10	removed	for bc in bcs: bc.set(b, x0, alpha) with b a NumPy array. For a PETSc vector, see set_bc.
Newton solver problem class	dolfinx.fem.petsc.NewtonSolverNonlinearProblem	removed	dolfinx.fem.petsc.NonlinearProblem, which solves with PETSc SNES and has a different interface
Point ownership search	determine_point_ownership(mesh, points, padding, cells=None)	adds find_closest_cell=True	Do not pass find_closest_cell