Extend aligned_membuf<> usage

[François Dumont]

On 05/02/2018 18:16, Jonathan Wakely wrote:
> On 01/02/18 22:48 +0100, François Dumont wrote:
>> Hi
>>
>> Â Â Â  As we just bump version namespace it might be interesting to do 
>> the following change now. What do you think ?
>
> I'd rather not make the code harder to read in all those places just
> for an optional mode that nobody uses.
>

I just consider this mode as a nice way to track all abi changes that we 
will be able to commit one day when we decide an abi breaking change.

> Wouldn't it make more sense to simply make __aligned_buffer identical
> to __aligned_membuf for the versioned-namespace? Then at least the
> conditional code is only in one place.
>
Yes, __aligned_buffer is indeed not used, we could do that. I'll propose 
a patch to do so.