Function chaining_impl

fn chaining_impl<'l, 'r, A: PartialOrd, B, C>(
    left: &'l [A],
    right: &'r [A],
    elem_chain: impl Fn(&'l A, &'r A) -> ControlFlow<B>,
    len_chain: impl for<'a> FnOnce(&'a usize, &'a usize) -> ControlFlow<B, C>,
) -> ControlFlow<B, C>