Hello, I'd like to share some functionality between states belonging to different (but similar) FSMs. I try to do this by taking out some part of a state to a base class template: template<class Derived, class Outer, class Inner> struct ActiveBase : state<Derived, Outer, Inner> { // this's probably not quite standard, but it should be fine with msvc ActiveBase(my_context ctx) : my_base(ctx) {} void f(const Event1 &) {} }; struct Active; struct FSM : asynchronous_state_machine<FSM, Active> { //... }; struct Active : ActiveBase<Active, FSM, Disconnected> { Active(my_context ctx) : ActiveBase(ctx) {} typedef mpl::list < sc::in_state_reaction<Event1, ActiveBase, &ActiveBase::f>
reactions; };
However, this doesn't compile: 1>..\boost/statechart/state_machine.hpp(493) : error C2440: 'return' : cannot convert from 'FSM' to 'ActiveBase<Derived,Outer,Inner> &' 1> with 1> [ 1> Derived=Active, 1> Outer=FSM, 1> Inner=boost::mpl::list<Disconnected> 1> ] 1> ../boost/statechart/simple_state.hpp(684) : see reference to function template instantiation 'Context &boost::statechart::state_machine<MostDerived,InitialState,Allocator,ExceptionTranslator>::context<OtherContext>(void)' being compiled 1> with 1> [ 1> Context=ActiveBase<Active,FSM,boost::mpl::list<Disconnected>>, 1> MostDerived=FSM, 1> InitialState=Active, 1> Allocator=std::allocator<void>, 1> ExceptionTranslator=boost::statechart::null_exception_translator, 1> OtherContext=ActiveBase<Active,FSM,boost::mpl::list<Disconnected>> 1> ] etc........ Of course, the above snippet is not the real code, and maybe I miss the problem in some other place, but I just would like to know if the above approach legitimate and *should* compile. Thanks.