Sorry for not replying earlier, Andreas Huber wrote:
Hi Alexander [skiped] So far I *think* I understand. You have developed a way how to represent/implement multimethods in C++. That's right. A little remark: I'm not finished it yet :)
The retrieval is a bit problematic but I'm working on this. The problem is a lack of typeof in C++. If it were available you could write:
template<int N, class C, class R, class T> mpl::identity<R(T)> tester(R (C::*)(overload_id<N>, T) const); typedef typeof(tester<0>(&read_number_transitions::operator()))::type sig0;
Here you lost me, tester does not seem to accept enough parameters. I assume that you'd need another parameter for the event. sig0 seems to have the same problem.
You're right. I missed it. Not a big problem, though. You can declare as many testers as you need to deduce arguments of a call operator with arbitrary arity (up to some reasonable value). They won't mess things up.
I don't exactly grok what follows but I guess it describes how to retrive the right functions given the current state type and an event type. You can then call the function to transition to the new state (the new state is returned). Yep.
Your mechanism only works with functions declared in a single class, right? Correct.
While I can see that an FSM framework can be built on top of this mechanism, I think I won't be able to use it in boost::fsm. A state machine implemented in terms of my library can be spread over multiple translation units (this is a key feature).
I like this feature.
I think your MM implementation (nice idea, BTW) could probably be used in a second FSM library, which is more oriented towards top-notch speed. boost::fsm focuses more on scalability (i.e. minimization of compile times of and dependencies in large FSMs). I agree.
Regards,
Andreas
-- Alexander Nasonov