[C++-sig] Re: indexing_v2 status update

[Joel de Guzman]

Raoul Gough wrote:
> David Abrahams <dave at boost-consulting.com> writes:
> 
> 
>>Joel de Guzman <joel at boost-consulting.com> writes:
>>
>>
>>>Raoul Gough wrote:
>>>
>>>
>>>>David Abrahams <dave at boost-consulting.com> writes:
>>>>
>>>>
>>>>>Joel de Guzman <joel at boost-consulting.com> writes:
>>>>
>>>>[snip]
>>>>
>>>>
>>>>>>Looks cool to me ;-) My only concern is: what if the bits of an
>>>>>>unsigned int runs out? Unlikely? What if the methods identifiers
>>>>>>are types instead in a special namespace and specifying the
>>>>>>methods is done using an mpl typelist? Example:
>>>>>
>>>>>One should at the very least use an unsigned long.  You're only
>>>>>guaranteed 16 bits with unsigned int.
>>>>
>>>>I thought about this, but figured there weren't any 16-bit compilers
>>>>that would compile the rest of the code anyway. Are there any real
>>>>platforms where the compiler supports all that template machinery and
>>>>has 16-bit ints (maybe some configurations of gcc)? I suppose it
>>>>doesn't actually cost anything to go to unsigned long...
>>>
>>>Maybe I ought to write the static bitset thing. I wrote one before.
>>>I'll see if I can get the prototype. There's one here:
>>>http://spirit.sourceforge.net/dl_more/Spirit_StaticSet.h
>>>I'll see if I can make it MPLish.
>>
>>It'd be easy to base it on vector_c<unsigned long, ....>

Yep. That's what I'm thinking.

> Something like this would be a good solution! Especially since it is
> possible to take the complement of a set (handy for saying "all
> features" or "all features except *this*"). However, it would need to
> have compile-time determination of set membership. Is this possible?

Yep. Sure!

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