https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114285
Xi Ruoyao <xry111 at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |xry111 at gcc dot gnu.org
--- Comment #9 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to Antoni from comment #8)
> Created attachment 57726 [details]
> Reproducer using union
>
> I tried switching to a union and I still get the same error.
>
> A union is used by std::optional, so I would assume that this should work.
> Or is copying uninitialized memory via a union also UB?
Yes.
std::optional copy constructor is not a default copy constructor. It does not
copy if the input is nullopt.
