Function range_zip::generate_impl

pub(crate) fn generate_impl(params: &Params) -> String

Output:

impl<Idx, IR0, R0, IR1, R1, IO0, O0, IO1, O1> Iterator
    for RangeZip2x2<Idx, IR0, R0, IR1, R1, IO0, O0, IO1, O1>
where
    Idx: std::cmp::Ord,
    IR0: Iterator<Item = (Idx, R0)>,
    IR1: Iterator<Item = (Idx, R1)>,
    IO0: Iterator<Item = (Idx, O0)>,
    IO1: Iterator<Item = (Idx, O1)>,
    O0: Clone,
    O1: Clone,
{
    type Item = (Idx, R0, R1, Option<O0>, Option<O1>);

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        let Self {
            r0,
            r1,
            o0,
            o1,
            o0_data_latest,
            o1_data_latest,
        } = self;

        let (r0_index, r0_data) = r0.next()?;
        let (r1_index, r1_data) = r1.next()?;

        let max_index = [r0_index, r1_index].into_iter().max()?;

        let mut o0_data = None;
        while let Some((_, data)) = o0.next_if(|(index, _)| index <= &max_index) {
            o0_data = Some(data);
        }
        let o0_data = o0_data.or(o0_data_latest.take());
        o0_data_latest.clone_from(&o0_data);

        let mut o1_data = None;
        while let Some((_, data)) = o1.next_if(|(index, _)| index <= &max_index) {
            o1_data = Some(data);
        }
        let o1_data = o1_data.or(o1_data_latest.take());
        o1_data_latest.clone_from(&o1_data);

        Some((max_index, r0_data, r1_data, o0_data, o1_data))
    }
}