bevy-trait-query 0.19.0

Implementation of trait queries for the bevy game engine
Documentation 
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pub(crate) struct ZipExact<A, B> {
    a: A,
    b: B,
}

impl<A: Iterator, B: Iterator> Iterator for ZipExact<A, B> {
    type Item = (A::Item, B::Item);
    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        let a = self.a.next()?;
        let b = self
            .b
            .next()
            // SAFETY: `a` returned a valid value, and the caller of `zip_exact`
            // guaranteed that `b` will return a value as long as `a` does.
            .unwrap_or_else(|| unsafe { crate::debug_unreachable() });
        Some((a, b))
    }
}

/// SAFETY: `b` must yield at least as many items as `a`.
#[inline]
pub(crate) unsafe fn zip_exact<A: IntoIterator, B: IntoIterator>(
    a: A,
    b: B,
) -> ZipExact<A::IntoIter, B::IntoIter>
where
    A::IntoIter: ExactSizeIterator,
    B::IntoIter: ExactSizeIterator,
{
    let a = a.into_iter();
    let b = b.into_iter();
    debug_assert_eq!(a.len(), b.len());
    ZipExact { a, b }
}