On 2023-01-14 17:51, Paul Eggert wrote:

> We already have two copies of that stuff elsewhere (in lib/stdalign.in.h 
> and m4/stdalign.m4), for reasons that currently escape me.

To try to address that in an upward-compatible way, I installed the 
attached. This shrinks the number of copies of that code down to one. 
The basic idea is to prefer C23 semantics in apps and the rest of Gnulib 
by using the new alignasof module, whereas the existing stdalign module 
is now for C11/C17 compatibility and is now deprecated.