https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120717
Patrick Palka <ppalka at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
CC| |ppalka at gcc dot gnu.org
Last reconfirmed| |2025-06-20
--- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> ---
> 1. Refine the implementation-detail metafunction
> std::__is_complete_or_unbounded so that it correctly handles such reference
> to incomplete types.
Makes sense, the warning demonstrates that __is_complete_or_unbounded
needlessly tries to instantiate the underlying type of a reference type (or
array of unknown bound).
> Option 1 appears to be unimplementable because such metafunction can be
> called several times in different contexts, which can result in ODR-violation.
I think ODR violation is only a risk if the sizeof check happens inside the
template definition. If the sizeof check only happens during template argument
deduction (e.g. encoded as a default template argument as it is now), that
shouldn't introduce ODR violations since the result of template argument
deduction can vary across a program, unlike template instantiation, IIUC.
