[postgis-devel] Validity flag

[Hugo Mercier]

On 29/02/2016 11:49, Sandro Santilli wrote:
> On Mon, Feb 29, 2016 at 10:36:54AM +0100, Hugo Mercier wrote:
>> Hi all,
>>
>> Following the Paris code sprint, I've proposed a pull request that
>> allows to manipulate a validity flag in geometries and use it in SFCGAL:
>>
>> https://github.com/postgis/postgis/pull/99
>>
>> First about the flag: it seems we now have the whole flag byte
>> populated. It then means there is no room for future flags ? Could we
>> keep a spare flag for an "extended" flag byte if needed someday ?
> 
> Sorry, are you saying we're using all 8 bits in current trunk (r14719) ?
> We _do_ want to keep one flag to extend the flagset, no dubt here.

The first bit in the byte is now documented as "Version". What does it
mean ? It is precisely to mark it as a future "extended" version ?