``None``
  Link with ``-cudart=none`` or equivalent flag(s) to use no CUDA
  runtime library.
``Shared``
  Link with ``-cudart=shared`` or equivalent flag(s) to use a
  dynamically-linked CUDA runtime library.
``Static``
  Link with ``-cudart=static`` or equivalent flag(s) to use a
  statically-linked CUDA runtime library.