[PATCH] D12747: Implement [depr.c.headers]

[Eric Fiselier via cfe-commits]

Patch #10 LGTM.

On Thu, Oct 8, 2015 at 4:28 PM, Richard Smith <richard at metafoo.co.uk> wrote:
> On Thu, Oct 8, 2015 at 11:50 AM, Marshall Clow <mclow.lists at gmail.com>
> wrote:
>>
>> On Tue, Oct 6, 2015 at 3:57 PM, Richard Smith <richard at metafoo.co.uk>
>> wrote:
>>>
>>> <stddef.h>. This one is tricky:
>>>
>>> 1) There's an (undocumented) interface between the C standard library and
>>> this header, where the macros __need_ptrdiff_t, __need_size_t,
>>> __need_wchar_t, __need_NULL, __need_wint_t request just a piece of this
>>> header rather than the whole thing. If we see any of those, just go straight
>>> to the underlying header.
>>
>>
>> Ok, but in that case we don't get nullptr.  I suspect that's OK.
>>
>>>
>>> 2) We probably don't want <stddef.h> to include <cstddef> (for
>>> consistency with other headers)
>>
>>
>> No, we do not! :-)
>>
>>>
>>> , but <stddef.h> must provide a ::nullptr_t (which we don't want
>>> <cstddef> to provide). So neither header includes the other. Instead, both
>>> include <__nullptr> for std::nullptr_t, and we duplicate the definition of
>>> max_align_t between them, in the case where the compiler's <stddef.h>
>>> doesn't provide it.
>>>
>>> If you prefer, I could make <stddef.h> include <cstddef> to avoid the
>>> duplication of the max_align_t logic.
>>
>>
>> No; this is a minor annoyance, and layer jumping (<stdXXX.h> including
>> <cstdXXX>) is a major annoyance - and I'm pretty sure that that would come
>> back to bite us in the future.
>>
>> Looks ok to me.
>
>
> Thanks, everything up to and including patch 09 is now committed.