Function rustfmt_nightly::vertical::group_aligned_items

fn group_aligned_items<T: AlignedItem>(
    context: &RewriteContext<'_>,
    fields: &[T],
) -> (&'static str, usize)

Returns the index in fields up to which a field belongs to the current group. The returned string is the group separator to use when rewriting the fields. Groups are defined by blank lines.