[Boost-users] Re: [variant] is_a/can_be

From: Yuval Ronen (ronen_yuval_at_[hidden])
Date: 2005-02-02 17:33:37

Eric Friedman wrote:
> Hi,
> 
> I can imagine cases where the current behavior might be preferable 
> (e.g., uses of variant types in generic contexts).  But I think for the 
> vast majority of cases, and especially in non-generic contexts, checking 
> the type as you propose is a good idea.
> 
> I will determine a way to work this into the library, either by 
> modifying the semantics of boost::get or by introducing a new accessor 
> function.  Thanks for the input.
> 
> Eric Friedman
> Co-author of Variant library

Great! Thanks a lot.

BTW, another two small remarks: The "variant::types" typedef that was 
used here is not documented, and it will be helpful if I could read 
about it and about its possible usages. And if you wish not to burden 
the users with mpl, then it's possible to wrap mpl::contains in a 
constant boolean value "can_be", as I suggested.

But anyway, thanks again.