https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54005
--- Comment #18 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Hans-Peter Nilsson from comment #16)
> (In reply to Jonathan Wakely from comment #14)
> > Can we close this?
>
> No. IIUC, we're still/again using __atomic_is_lock_free with alignment
> deduced from the current object rather than the type (even though it's now a
> proxy-object; the faked pointer is constructed from the alignment of the
> current object).
It's constructed from __alignof(_M_i) and since r221945 that is given a fixed
alignment:
static constexpr int _S_alignment =
sizeof(_ITp) > alignof(_ITp) ? sizeof(_ITp) : alignof(_ITp);
alignas(_S_alignment) __int_type _M_i;
So it will be the same for all objects of the type.
There was an additional fix in r227878 for Bug 65913.
> So, r221701 was wrong to change from null to the alignment-deduced
> fake-pointer.
I think the current code is right, and per-type.
I still want to close this.
