Function veho::matrix::mapflat

pub fn mapflat<R, M, T, J, F>(matrix: M, indicator: J, sequence: F) -> Option<T> where
    M: IntoIterator<Item = R>,
    R: IntoIterator,
    M::IntoIter: Iterator<Item = R>,
    R::IntoIter: Iterator<Item = R::Item>,
    J: FnMut(R::Item) -> T,
    F: FnMut(T, R::Item) -> T,