direct threading support), 6, 8.</li>
  </ul>

  <p>I believe Boost.Statechart satisfies all requirements.</p>

  <h2><a name="StateLocalStorage" id="StateLocalStorage">State-local
  storage</a></h2>

  <p>This not yet widely known state machine feature is enabled by the fact
  that every state is represented by a class. Upon state-entry, an object of
  the class is constructed and the object is later destructed when the state
  machine exits the state. Any data that is useful only as long as the
  machine 