I am a new user of the Boost MSM library and I was wondering how to post internal events. It seems that only events can be sent from the back end, am I wrong?
Yes they can only be sent from the back-end but it it shouldn't be a problem. You can define a functor doing this (http://svn.boost.org/svn/boost/trunk/libs/msm/doc/HTML/ch03s03.html#d0e1298), for example: struct store_cd_info { template <class Fsm,class Evt,class SourceState,class TargetState> void operator()(Evt const&, Fsm& fsm, SourceState&,TargetState& ) { fsm.process_event(play()); } }; The "Fsm" template parameter is the back-end. With eUML you also have a process_ function. Only the basic front-end really is too simple. Inside this front-end, you could static_cast to the back-end type but this would really not be a good solution, so I advise you to switch to the more powerful front-ends, or to at least mix and use a "Row" instead of the xxx_row versions for the transitions when you need to post another event (you can mix row types). HTH, Christophe