`GenIter` is panicking after call `.next()` after completion

[uselessgoddess]

Your generator is panicking thread 'main' panicked at 'generator resumed after completion'

let mut generator = gen_iter! {{
    yield 1;
}};

println!("{:?}", generator.next());
println!("{:?}", generator.next());
println!("{:?}", generator.next());

[viruscamp]

It was designed as this, to minimize the memory footprint of GenIter<T>.
It's recommended to use GenIter<T> in for loop instead of call next manually.

[Boscop]

@uselessgoddess What if you call .fuse() on the iterator, does it still panic if you keep calling next?