struct S<const C: usize>
where
    [(); { num_slots!(C) }]:, {
    /* An asterisk-based, or a double-slash-prefixed, comment here is
       required to trigger the fmt bug.

    A single-line triple-slash-prefixed comment (with a field following it) is not enough - it will not trigger the fmt bug.

    Side note: If you have a combination of two, or all three of the
    above mentioned types of comments here, some of them disappear
    after `cargo fmt`.

    The bug gets triggered even if a field definition following the
    (asterisk-based, or a double-slash-prefixed) comment, too.
    */
}