rust/tests/ui/zero-sized/zero-sized-linkedlist-push.rs

// run-pass
use std::collections::LinkedList;
use std::iter::Iterator;

fn main() {
    const N: usize = 8;

    // Test that for all possible sequences of push_front / push_back,
    // we end up with a LinkedList of the correct size

    for len in 0..N {
        let mut tester = LinkedList::new();
        assert_eq!(tester.len(), 0);
        assert_eq!(tester.front(), None);
        for case in 0..(1 << len) {
            assert_eq!(tester.len(), 0);
            for bit in 0..len {
                if case & (1 << bit) != 0 {
                    tester.push_front(());
                } else {
                    tester.push_back(());
                }
            }
            assert_eq!(tester.len(), len);
            assert_eq!(tester.iter().count(), len);
            tester.clear();
        }
    }
}