https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61982
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(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.
