MSM Documentation (section: Explicit Entry): --------------------------------------------- You can then use it as target in a transition with State1 as source: _row < State1, Event2, SubFsm2::direct< SubFsm2_::SubState2> > The syntax deserves some explanation. SubFsm2_ is a front end. SubState2 is a nested state, therefore the SubFsm2_::SubState2 syntax. The containing machine (containing State1 and SubFsm2) refers to the backend instance (SubFsm2). SubFsm2::direct states that an explicit entry is desired.

So I think the code snippet has to look like as follows (SubFsm2 instead of SubFsm2_): _row < State1, Event2, SubFsm2::direct< SubFsm2::SubState2> >

Actually not but I might need to detail a bit. Consider: struct SubFsm2_ ... // front-end { struct SubState2 ... // ---> nested type }; typedef msm::back::state_machine<SubFsm2_> SubFsm2; //back-end SubFsm2_ : front-end SubFsm2: back-end SubFsm2_::SubState2 : the complete name of SubState2. Which means that : _row < State1, Event2, SubFsm2::direct< SubFsm2_::SubState2> > is correct. The back-end(SubFsm2) provides a direct entry type (SubFsm2::direct<>) taking as argument the direct entry state, which name is SubFsm2_::SubState2. Regards, Christophe