gistfile1.txt

pub trait AsRev {
    fn as_rev(&self) -> &ListItem;
}

impl AsRev for ListItem {
    fn as_rev(&self) -> &ListItem {
        &self
    }
}

impl<'a> AsRev for &'a ListItem {
    fn as_rev(&self) -> &ListItem {
        self
    }
}

pub struct ListItem {
    pub pre_comment: Option<String>,
    // Item should include attributes and doc comments.
    pub item: String,
    pub post_comment: Option<String>,
    // Whether there is extra whitespace before this item.
    pub new_lines: bool,
}

pub fn definitive_tactic<'t, I, T>(items: I,
                                tactic: ListTactic,
                                width: usize)
                                -> DefinitiveListTactic
    where I: IntoIterator<Item = T> + Clone,
          T: AsRev
{
}