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Re: [PATCH] Add a new type attribute always_alias (PR79671)
On Mon, Apr 10, 2017 at 11:30 AM, Richard Biener <rguenther@suse.de> wrote:
> On Mon, 10 Apr 2017, Jason Merrill wrote:
>> On Mon, Apr 10, 2017 at 8:50 AM, Richard Biener <rguenther@suse.de> wrote:
>> > * tree.c (build_cplus_array_type): Set TYPE_TYPELESS_STORAGE
>> > for arrays of unsigned char or std::byte.
>>
>> I think it would be good to have a flag to select whether these
>> semantics apply to any char variant and std::byte, only unsigned char
>> and std::byte, or only std::byte.
>
> Any suggestion? Not sure we really need it (I'm hesitant to write
> all the testcases to verify it actually works).
Well, there's existing code that uses plain char (e.g. boost) that I
want to support. If there's a significant optimization penalty for
allowing that, we probably also want to be able to limit the impact.
If there isn't much penalty, let's just support all char variants.
Jason