Macro gen_iter::gen_iter

macro_rules! gen_iter {
    ($($exp:tt)*) => { ... };
}

macro to simplify iterator - via - generator construction

let mut g = gen_iter! {
    yield 1;
    yield 2;
};


assert_eq!(g.next(), Some(1));
assert_eq!(g.next(), Some(2));
assert_eq!(g.next(), None);