shared
======

.. py:function:: t3toolbox.shared_geometry.shared(base, sharing)

   .. code-block:: python

      def shared(
              base,                       # MANIFOLD / COREWISE / UNIFORM_MANIFOLD / UNIFORM_COREWISE
              sharing:    typ.Sequence,   # len=d; one hashable group label per mode
      ) -> SharedGeometry:


   The shared (SF-T3) geometry over a base geometry: optimize with the Tucker factors tied
   within each sharing group. Equal wrappers compare equal (a stable jit aux). Uniform bases
   take/return the uniform objects (``UniformTuckerTensorTrain`` / ``UT3Frame`` / ``UT3Tangent``)
   and run the packed compile-once fitting path.