> The ways we've discussed using aligned allocation in numpy wouldn't follow this requirement without special checking. Which isn't necessarily a big deal, and numpy won't necessarily use this API anyway. But I would suggest being very clear about exactly what you guarantee and what you don't :-).

In the GitHub issue we sort of decided to make the more relaxed Posix
semantics official:

'alignment' must be a power of 2 and a multiple of 'sizeof(void *)'.

'size' can be really anything, so it should work for numpy.

It's a pity that Posix does not round up align={1,2,4} to 'sizeof(void *)'
automatically (why not?), so the applications will have to do that.