https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61982
--- Comment #11 from hyrosen at mail dot com ---
(In reply to Jakub Jelinek from comment #10)
> (In reply to hyrosen from comment #9)
> > The storage for an object can still be accessible after the object is
> > destroyed. Therefore, writes in the destructor should not be eliminated
> > unless they are provably inaccessible:
> >
> > struct X { int i; ~X() { i = 0; } };
> >
> > void destroy(X &x) { x.~X(); }
> >
> > int main()
> > {
> > alignas(X) char buf[sizeof(X)], save[sizeof(X)];
> > X *x = new (buf) X;
> > x->i = 1;
> > memcpy(save, buf, sizeof(X));
> > destroy(*x);
> > assert(memcmp(buf, save, sizeof(X)) != 0);
> > }
>
> No, that invokes UB.
Do you have a reference that demonstrates that?
