https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83912
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org,
| |jason at gcc dot gnu.org,
| |nathan at gcc dot gnu.org
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I think for this to work the NRV optimization would need to happen very early
so that we see that the c3.m_ptr field is actually &c3.m_value rather than
&<temporary>.m_value for a temporary that will be later on NVR optimized to the
RESULT_DECL and eventually to c3. If you do:
void
foo ()
{
constexpr auto c_4 = make_instance(34);
}
clang++ rejects it too. So the question is, does the standard mandate NRV to
happen here in the c_3 case and when the NRV optimization happens wrt.
constexpr evaluation.
