https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119325
--- Comment #15 from Richard Biener <rguenth at gcc dot gnu.org> --- maybe #define RESIZE_VECTOR(to_t, from) \ ({ \ __auto_type __from = (from); \ to_t __to; memcpy (&__to, &__from, MIN (sizeof (to_t), sizeof (from))); \ __to; \ })