// 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(); } } }