title: Using numpy.broadcast() on ndarray duck types
body: <p>I've been trying to implement my own custom array container using <a href="https://numpy.org/doc/stable/user/basics.dispatch.html" rel="nofollow noreferrer">numpy's documentation</a> and I'm having trouble getting <code>numpy.broadcast()</code> to work with my container. I've defined <code>__array_function__</code> for my custom array container, but it isn't called when using <code>numpy.broadcast()</code>.</p>
  <p>Is it correct that <code>numpy.broadcast()</code> doesn't use the <code>__array_function__</code> infrastructure? If so, is there any way to make a custom array container compatible with <code>numpy.broadcast</code>?</p>