void *zrealloc_usable(void *ptr, size_t size, size_t *usable) {
    ptr = ztryrealloc_usable(ptr, size, usable);
    if (!ptr && size != 0) zmalloc_oom_handler(size);
    return ptr;
}
void *zrealloc_usable(void *ptr, size_t size, size_t *usable) {
    ptr = ztryrealloc_usable(ptr, size, usable);
    if (!ptr && size != 0) zmalloc_oom_handler(size);
    return ptr;
}