[boost] Re: Variant (aka Discriminated Union) implementation

From: Andrei Alexandrescu (andrewalex_at_[hidden])
Date: 2002-07-05 11:30:53

"Itay Maman" <itay_maman_at_[hidden]> wrote in message
"Eric Friedman" wrote:
[snip]
> * Generic visitation by any functionable object.
>
>   This is *very* powerful; nearly all of variant's internal features
>   are implemented in terms of generic (templated) visitation.
>

I saw that that feature uses a cascading set of if-else statements.
The theorist in me worries about this non-scalability, although in
practice that might often be ok with small typelists. Also, the
practical person in me still doesn't find using mpl for Variant
palatable.

>(2) I'd like to repeat my view: given the fact that the two varaint
implementations are getting more and more identical, the two
implementations should be integrated into single library. I still
believe that the most effective approach, would be for us to
co-develop this (unified) variant library.<

I think that would be cool, too, and I believe Itay's code is a better
starting point for the reasons above.

Andrei