gat-lending-iterator 0.1.8

A library for iterators who's items can [mutably] reference the iterator.
Documentation 
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use crate::LendingIterator;

/// A lending iterator that iterates over an iterator.
#[derive(Clone)]
pub struct IntoLending<I: Iterator> {
    iter: I,
}

impl<I: Iterator> IntoLending<I> {
    pub(crate) fn new(iter: I) -> Self {
        Self { iter }
    }
}

impl<I: Iterator> LendingIterator for IntoLending<I> {
    type Item<'a>
        = I::Item
    where
        Self: 'a;

    fn next(&mut self) -> Option<Self::Item<'_>> {
        self.iter.next()
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        self.iter.size_hint()
    }
}

#[cfg(test)]
mod tests {
    use crate::{LendingIterator, ToLendingIterator};

    fn double_i32(x: i32) -> i32 {
        x * 2
    }

    #[test]
    fn into_lending_basic() {
        let result: Vec<_> = vec![1, 2, 3]
            .into_lending()
            .map(double_i32)
            .into_iter()
            .collect();
        assert_eq!(result, vec![2, 4, 6]);
    }
}