[boost] Re: [OBORONA-SPAM] RE: Re: overloads-20050207.tar.gz

From: David Abrahams (dave_at_[hidden])
Date: 2005-02-13 16:01:17

"Alexander Nasonov" <alnsn_at_[hidden]> writes:

> David Abrahams wrote:
>> I'll ask again: what is the point of using types for states?
>
> You can't easily emulate is-a relationship with numbers. With classes you
> just derive one class from another. 

Okay, but what's the value of modeling an is-a relationship between
states?  In a FSM, states are distinct.  One state is-not-a nother
state.

> My example demonstrates this technique.

AFAICT it seems to be a way of grouping states, or perhaps of
emulating substates, so you can avoid writing the transitions
that a group of states has in common (?)

>> I don't know if I do so, yet ;-)
>
> I mean I _can_ do so but switching to mpl concept doesn't go smoothly.
> Currently, I'm trying to understand why size of mpl::set<id<1>, id<2> > is 2
> while distance between  begin and end is one?

I'm lost, sorry.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com