On 10/03/2022 20:20, Zhihao Yuan via Std-Proposals wrote:
>
> But other than the built-in array,
> no operator[] in the standard is
> aware of value-category (std::array,
> std::vector, etc.) The built-in
> array is special here as its "[i]"
> models after a member access.

To be honest, this prompts the question as if this was an oversight
(does std::array predate move semantics?) or a deliberate design
decision to align with e.g. std::vector.

(I can understand why std::vector operator[] hasn't been changed to
return rvalue references invoked on a rvalue vector.)

Thanks,

-- 
Giuseppe D'Angelo