jax_or_warn
===========

.. py:function:: t3toolbox.backend.common.jax_or_warn(what)

   .. code-block:: python

      def jax_or_warn(what: str) -> bool:


   The jax-absent policy: a request for jax (``use_jax=True``, ``to_jax``, ``use_jit=True``) on a machine
   without jax runs on numpy and WARNS, once per call site -- never an error (a project developed without
   jax on one machine and deployed with it on another must run unchanged on both), never silent (the old
   ``to_jax = np.array`` fallback). Returns ``jax_available``.