((size_t *)mem)[-1] = header&7 | new-mem;
((size_t *)new)[-2] = footer&7 | new-mem;
((size_t *)new)[-1] = header&7 | end-new;
((size_t *)mem)[-1] = header&7 | new-mem;
((size_t *)new)[-2] = footer&7 | new-mem;
((size_t *)new)[-1] = header&7 | end-new;