HI Boost-users/christophe, I'm trying to make use of type erasure for fsm based on suggestion from an earlier mail thread http://boost.2283326.n4.nabble.com/msm-access-to-root-fsm-td4649632.html but hitting compilation errors. Can you pls help? while the any works as expected for push back e.g for vector (bottom of email) it doesnt work for MSM.. *Doesn't Work for MSM:* BOOST_TYPE_ERASURE_MEMBER((has_process_event), process_event, 1) typedef any<has_process_event<HandledEnum(Event1 const &)>, _self&> any_fsm; struct AnyFSM { AnyFSM(any_fsm afsm_) : _afsm(afsm_) {} void process(Event1& e) { _afsm.process_event(e); } any_fsm _afsm; }; TestFSM test; test.start(); AnyFSM(test); test.process(Event1()); *error:* *test.cpp:47:43: **error: **'Event1' does not refer to a value* typedef any<has_process_event<HandledEnum(Event1 const &)>, _self&> any_fsm; *Works for vector:* BOOST_TYPE_ERASURE_MEMBER((has_push_back), push_back, 1) typedef any<has_push_back<void(int)>, _self&> any_container; void append_many(any_container container) { for(int i = 0; i < 10; ++i) container.push_back(i); } struct AnyContainer { AnyContainer(any_container cont_) : _cont(cont_) {} void append() {append_many(_cont); } any_container _cont; }; AnyContainer m(v); m.append(); for(auto i : v) { std::cout << i << std::endl; } Thanks -Raj