Function veho::matrix::reduce

pub fn reduce<R, M, F>(matrix: M, f: F) -> Option<R::Item> where
    M: IntoIterator<Item = R>,
    R: IntoIterator,
    M::IntoIter: Iterator<Item = R>,
    R::IntoIter: Iterator<Item = R::Item>,
    F: FnMut(R::Item, R::Item) -> R::Item,