/* { dg-additional-options "-std=gnu89" } */
x(const char *s) {
    char a[1];
    const char *ss = s;
    a[*s++] |= 1;
    return (int)ss + 1 == (int)s;
}
main() {
    if (x("") != 1) abort();
    exit(0);
}
