[libc++ patch] Make meta.trans.other/aligned_storage.pass.cpp pass on arm

[Nico Weber]

On Wed, May 28, 2014 at 4:04 PM, Marshall Clow <mclow.lists at gmail.com>wrote:

>
> On May 28, 2014, at 4:36 AM, Nico Weber <thakis at chromium.org> wrote:
>
> > Hi,
> >
> > On arm, the maxium alignment is 8. The attached patch tweaks
> meta.trans.other/aligned_storage.pass.cpp so that it passes on arm. (The
> test currently assumes that alignment goes up to at least 16.)
>
> Nico —
>
> I’m a bit leery of
>         + static_assert(std::alignment_of<T1>::value == alignof(T1), "");
> b/c I’m not sure that it tests what we want to test here.
>
> Is there some way that we can use max_align_t in this test?
>
> Maybe something like (untested code):
>         static_assert (  std::alignment_of<T1>::value == std::max(16,
> alignof(std::max_align_t));
>

Why the max? On arm, alignof(max_align_t) is 8 (just like alignof(T1)), so
max(16, alignof(max_aling_t)) is 16, while std::alignment_of<T1>::value is
8.

    static_assert(std::alignment_of<T1>::value ==
                  alignof(std::max_align_t), "");

does work though, if you like that better. Should I just
s/alignof(T1)/alignof(std::max_align_t)/ in my patch?


>
> — Marshall
>
>
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