Hi there, I use MSM from boost 1.49 with VC9 on Windows XP. I want to use the eUML front end. My states shall use a polymorphic base class and are defined like this: // State base class struct Worker { virtual void work() = 0; }; // a state struct Running_ : msmf::state<Worker>, euml_state<Running_> { void work() { ... } } const Running; My transition table is defined with BOOST_MSM_EUML_TRANSITION_TABLE() My state machine is defined like this: BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( trans_table, init_ << AnyState, no_action, // fsm_entry no_action, // fsm_exit attributes_ << one_attr << another_attr, configure_ << no_configure_, Log_No_Transition, Log_Exception), MyFSM_fe) struct FSM : msmb::state_machine<MyFSM_fe> {}; All OK until here. But now I want to add the state base class to the above invocation of BOOST_MSM_EUML_DECLARE_STATE_MACHINE to be able to say : fsm.get_state_by_id(fsm.current_state()[0])->work() at any given time. BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( trans_table, init_ << Running, no_action, // fsm_entry no_action, // fsm_exit attributes_ << one_attr << another_attr, configure_ << no_configure_, Log_No_Transition, Log_Exception, Worker), MyFSM_fe) But this gives me a compile error: C2275: 'Worker' : illegal use of this type as an expression. Is there any way to achieve what I need ? Can I somehow _NOT_ use the macro and create the same state machine (i.e. with attributes!) ? Thanks for any help! Stefan -- ---------------------------------------------------------------- /dev/random says: A Bugless Program is an Abstract Theoretical Concept. python -c "print '73746566616e2e6e616577654061746c61732d656c656b74726f6e696b2e636f6d'.decode('hex')" GPG Key fingerprint = 2DF5 E01B 09C3 7501 BCA9 9666 829B 49C5 9221 27AF