Hello, having trouble getting this to work. Here’s a simplification of what I’m trying: //states and events defined elsewhere struct sub_fsm : public msm::front::state_machine_def<sub_fsm, state_base> { typedef entry_state_impl initial_state; BOOST_MSM_EUML_DECLARE_TRANSITION_TABLE(( entry_state + some_event() / action1 == next_state ), transition_table) sub_fsm() : pctx_(nullptr) {} sub_fsm(context *p) : pctx_(p) {} context *pctx_; }; typedef msm::back::state_machine<sub_fsm> sub_helper; struct sub_machine : public sub_helper, public msm::front::euml::euml_state<sub_helper> { sub_machine() {} sub_machine(context *p) : sub_helper(p) {} }; sub_machine const sub; struct outer_fsm : public msm::front::state_machine_def<outer_fsm, state_base> { typedef outer_entry_state_impl initial_state; BOOST_MSM_EUML_DECLARE_TRANSITION_TABLE(( outer_entry_state + another_event() / action2 == sub ), transition_table) outer_fsm() : pctx_(nullptr) {} outer_fsm(context *p) : pctx_(p) {} context *pctx_; }; typedef msm::back::state_machine<outer_fsm> outer_machine; int main() { context ctx; outer_machine fsm(msm::back::states_ << sub_machine(&ctx), &ctx); } This doesn’t compile under VC2010, it can’t deduce the template arguments for operator <<(). Am I on the right track here? Should the template parameter of euml_state<> really be sub_helper and not sub_machine (I got that chunk of code from here: http://svn.boost.org/svn/boost/trunk/libs/msm/doc/HTML/examples/CompositeTut... What am I doing wrong? Thanks for any help, Mark -- http://www.fastmail.fm - Choose from over 50 domains or use your own