The way 'auto', 'auto &' and 'decltype(auto)' for structural bindings works
has been an annoyance for me in more than one case... I'd love to make the
'auto [a, b]' mean "a and b are pure values, despite what the tuple
elements are' and 'auto& [a, b]' to mean "if the tuple-like to bind is an
lvalue ref then a and b references the elements in that tuple. Else if the
tuple-like is not an lvalue reference but the elements themselves are, then
a and b are the same as those references. And if none of those conditions
are satisfied the program is ill formed". But that may break any currently
working code, as code may rely on 'auto [a, b]' to actually be references..

The case with 'swap' is mitigated as minmax returns const&, not just &.

// Robin

// Robin

On Fri, Mar 7, 2025, 00:21 Sebastian Wittmeier via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> Perhaps we have to deprecate auto? ;-)
>
>
> -----Ursprüngliche Nachricht-----
> *Von:* Ell via Std-Proposals <std-proposals_at_[hidden]>
>
> This was discussed on reddit recently [1]. As noted there, the problem
> is broader than just dangling references to temporaries. The presence of
> unintended references is itself an issue:
>
> auto [min, max] = std::minmax (x, y); // x and y are lvalues
> std::swap (x, y); // oops, also swaps min and max
>
> I'd be wary of special-casing just the rvalue-argument case.
>
> [1]
>
> https://old.reddit.com/r/cpp/comments/1j2139v/c_creator_calls_for_action_to_address_serious/mfornic/
>
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