Paul Eggert wrote: > Oh, I was thinking the other way: a compiler that says it's C11 but doesn't > support _Atomic.
I haven't found such a compiler in my testing [1]. If one appears, we can add an ad-hoc test or an Autoconf test. Bruno [1] https://lists.gnu.org/archive/html/bug-gnulib/2020-10/msg00068.html
