pub fn from(to: &'a mut VecDeque<T>, from: &'b VecDeque<T>) -> Self {
        let (a0, a1) = to.as_mut_slices();
        let (b0, b1) = from.as_slices();
        PairSlices { a0, a1, b0, b1 }
    }
A double-ended queue implemented with a growable ring buffer.

The "default" usage of this type as a queue is to use [`push_back`] to add to
the queue, and [`pop_front`] to remove f
benchmarks/haystacks/code/rust-library.rs