A sketch of how to iterate over a list of references

into_refs.rs

pub trait IntoRefs<'a, T: 'a> {
    type Iterator: Iterator<Item = &'a T>;

    fn into_refs(self) -> Self::Iterator;
}

impl<'a, T> IntoRefs<'a, T> for &'a [T] {
    type Iterator = std::slice::Iter<'a, T>;
    fn into_refs(self) -> Self::Iterator {
        self.into_iter()
    }
}

impl<'a, T> IntoRefs<'a, T> for &'a [&'a T] {
    type Iterator = std::iter::Copied<std::slice::Iter<'a, &'a T>>;
    fn into_refs(self) -> Self::Iterator {
        self.into_iter().copied()
    }
}

// TODO: this will benefit from const generics!
impl<'a, T> IntoRefs<'a, T> for &'a [&'a T; 1] {
    type Iterator = std::iter::Copied<std::slice::Iter<'a, &'a T>>;
    fn into_refs(self) -> Self::Iterator {
        self.into_iter().copied()
    }
}

impl<'a, T> IntoRefs<'a, T> for Vec<&'a T> {
    type Iterator = std::vec::IntoIter<&'a T>;
    fn into_refs(self) -> Self::Iterator {
        self.into_iter()
    }
}