Re: [boost] BOOST_PP array extension proposal

Subject: Re: [boost] BOOST_PP array extension proposal
From: Edward Diener (eldiener_at_[hidden])
Date: 2015-09-11 19:13:35

On 9/11/2015 6:46 PM, Paul Mensonides wrote:
> On 9/11/2015 3:40 PM, Edward Diener wrote:
>> On 9/11/2015 4:58 PM, Paul Mensonides wrote:
>>> On 9/11/2015 6:37 AM, Edward Diener wrote:
>
>>> Wait... what would be considered an empty tuple or sequence?
>>
>> "Emptiness" or no preprocessor token.
>
> So:
>
> size 0:
> size 1: ()
> size 2: (,)
> size 3: (,,)
>
> ?

Yes.

Also I will rewrite a number of BOOST_PP_TUPLE_XXX macros as 
BOOST_VMD_TUPLE_XXX macros to allow for starting with emptiness or 
ending with emptiness.

I will do the same for seq.

Of course emptiness does not have to be treated as a tuple or a seq, but 
will be in my rewritten macros as appropriate.

VMD is the place for this functionality since Boost PP does not have to 
support variadic macros to still work, and testing for emptiness without 
using variadic macros is too flawed to use IMO.