[Bug libstdc++/121180] std::any allows for creating multiple empty objects of the same type at the same address

[luigighiron at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121180

--- Comment #10 from Halalaluyafail3 <luigighiron at gmail dot com> ---
(In reply to Tomasz Kamiński from comment #9)
> The situation when such issue can arise is dynamic condition, so this will
> entail disabling small object optimization entirely. I think the issue is an
> defect in the standard, as the standard is meant to allow SSO, and thus
> stored object to be nested withing any.
For objects that are an empty class or that contain an empty class, I think it
should still be fine for other objects that would never be able to overlap with
std::any or a byte array.

I think it would be worth making an issue for this, either with CWG or LWG. Not
sure which would make more sense here.