Function axpy 

pub fn axpy<D, S, A, Op>(
    dest: &mut StridedViewMut<'_, D>,
    src: &StridedView<'_, S, Op>,
    alpha: A,
    exec: Exec<'_>,
) -> Result<()>
where
    A: Copy + Mul<S, Output = D> + Sync,
    D: Copy + Add<D, Output = D> + Send + Sync,
    S: Copy + Send + Sync,
    Op: ElementOp<S>,

AXPY: dest[i] = alpha * src[i] + dest[i].

Alpha, source, and destination may have different element types.