Yes, it can, and it already does: there is an explicit deduction guide for std::array that deduces the array size.

Cheers,
Timur

> On 27 Sep 2019, at 16:00, Vladimir Grigoriev via Std-Discussion <std-discussion_at_[hidden]> wrote:
>
> In the Standard in the section devoted to the deduction guide there is nothing said what template parameters may be used.
>
> So a question arises whether non-type template parameters can be used in a deduction guide? That is can a deduction guide deduce a non-type parameter? If not then the Standard should explicitly say about this restriction.
>
> With best regards,
> Vlad from Moscow
>
> You can meet me at http://cpp.forum24.ru/ or www.stackoverflow.com or http://ru.stackoverflow.com
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