Re: [boost] [variant, MPL] Is there a variant -> mpl sequence metafunction ?

From: Joel de Guzman (joel_at_[hidden])
Date: 2006-11-13 13:17:01

David Abrahams wrote:
> Joel de Guzman <joel_at_[hidden]> writes:
> 
>> Jaakko Järvi wrote:
>>> On May 17, 2005, at 10:22 PM, Larry Evans wrote:
>>>
>>>> On 05/17/2005 10:07 PM, Jaakko Järvi wrote:
>> [...]
>>
>>>> I'd suggest making variant part of mpl.  With that, the problem
>>>> disappears.
>>> Yes, variant, mpl, tuple (or fusion), should play well together.
>>> A good first step would be to start using the same type to mark that
>>> no type was specified (instead of the variations void_, null_t, ...).
>> FYI, variant is now a valid fusion sequence. 
> 
> I don't get it.  What are the values of the non-stored elements?

Default constructed *only* when dereferenced. Iteration only does
not touch the data.

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net