Re: [Boost-users] formal review of Switch library ends tomorrow (Wednesday, January 9th) - reviews needed

From: Steven Watanabe (steven_at_[hidden])
Date: 2008-01-10 20:25:48

AMDG

Tobias Schwinger <tschwinger <at> isonews2.com> writes:

> > Now that that's cleared, let me /push/ now the other benefits
> > of my proposed interface:
> > 
> > * Ability to allow fall-through and break:
> > 
> >        case_<1>(f1, break_), // no fall-through
> >        case_<2>(f2),         // fall-through (by default)
> > 
> > * Allow multiple case handling:
> > 
> >        case_<'x', 'y'>(f2),  // handle 'x' and 'y'
> > 
> 
> This stuff is pretty cool. But it -again- makes me think we are in fact
> talking about two different kinds of switch tools: One that can be used
> manually with lots of syntactic sugar - and another one that's mean and
> lean and doesn't have to be that pretty because it's intended to be fed
> its input in form of an automatically computed sequence, anyway...

I'm inclined to agree.

Regarding multiple case handling,
there have to be two layers.  The outer layer exposed to
the user has to separate everything into separate cases,
possibly using a no-op function that falls through.  Expanding
the sequence seems a bit too heavy weight for me.  I would
at least want to have the internal dispatching function
exposed directly so that those who don't need this kind of
fanciness don't have to pay for it.

In Christ,
Steven Watanabe