Hi,<br><br>I think that the visitors and the flags ideas of the MSM are very generic and easy to use.<div>So, great!</div><div><br>But, there is a way to define multiple visitors for a single state (base)?</div><div>I think that it is not possible because the visitors mechanism is based on a &quot;simple/single typedef&quot; and not on an &quot;listed typedef&quot;... isn&#39;t it?</div>

<div><br>So, why the visitors are not like flags?</div><div>I mean, why not to use an &quot;accept_sig_list&quot; instead of a single &quot;accept_sig&quot;?</div><div>Why is not possible a code like the following:<br><br>

struct my_visitable_state<br>{<br>  typedef mpl::vector&lt; args&lt;void, VisitorType1&amp;&gt;,  args&lt;void, VisitorType2&amp;&gt; &gt; accept_sig_list;</div><div> <br><div>   void accept(VisitorType1&amp;) const {}</div>

<div><div>  void accept(VisitorType2&amp;) const {}</div>};</div><div><br></div></div><div><br></div><div>By the way... I think that the usage of boost::ref() is not propagated to the submachines...? </div><div>I&#39;ve found that when my state machine is also in a submachine, the visitor of the state machine is passed by reference, but the submachine is passed always by value... is this a bug?</div>

<div>(just using a pointer solved my needs, so just to report...)</div><div><br></div><div><br></div><div>Thanks,</div><div><br></div><div><br></div><div>Albert</div><div><br></div>