Contributions after C++23 mdspan.

[Jonathan Wakely]

On Thu, 5 Jun 2025, 08:56 Tomasz Kaminski, <tkaminsk@redhat.com> wrote:

>
>
> On Wed, Jun 4, 2025 at 6:03 PM Luc Grosheintz <luc.grosheintz@gmail.com>
> wrote:
>
>> > Firstly, thank you very much for your contributions, they are really
>> > appreciated.
>>
>> Thank you! I'm glad to hear it.
>>
>> > One option would be to continue with mdspan later mappings, but I will
>> > understand
>> > if you would like to take a break from the topic.
>>
>> Locally, I have "complete" patches for: default_accessor and mdspan.
>> I'll start sending them soon. I don't want to send too much at once.
>>
>> This is (a roundabout version of) the email asking if I can start
>> preparing layout_{left,right}pad (and then keep going until the
>> we finish all md-related C++26 features)?
>>
>
> After a bit of consideration, I would greatly appreciate if you could look
> into implementing
> this one, we are working on stabilizing C++20, and consider having this
> change as DR for
> span (so we want implementation that will work in C++20):
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p3029r0.html
>

Ah yes, good idea. Since that affects C++20 or would be good to do sooner.




> Afterwards, I agree that working on padded layout makes a lot of sense,
> even landing them
> before we will start looking into "optimizing" indexing computation. I
> would consider updating
> __linear_index_left to accept the first extent.
>
> Regards,
> Tomasz
>
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