Function beagle::scalar_array::vec_array::cross

pub fn cross<S, T>(
    s: CustomArrayThree<S>, 
    t: CustomArrayThree<T>
) -> CustomArrayThree<S::Output> where
    S: Clone + Mul<T>,
    T: Clone,
    S::Output: Sub<Output = S::Output>, 

Fold all the elements in a 1d array. The first element is mapped with f0, then folding continues with f for other elements.