//@ run-pass #![allow(non_camel_case_types)] trait methods { //~ WARN trait `methods` is never used fn to_bytes(&self) -> Vec; } impl methods for () { fn to_bytes(&self) -> Vec { Vec::new() } } // the position of this function is significant! - if it comes before methods // then it works, if it comes after it then it doesn't! fn to_bools(bitv: Storage) -> Vec { (0..8).map(|i| { let w = i / 64; let b = i % 64; let x = 1 & (bitv.storage[w] >> b); x == 1 }).collect() } struct Storage { storage: Vec } pub fn main() { let bools = vec![false, false, true, false, false, true, true, false]; let bools2 = to_bools(Storage{storage: vec![0b01100100]}); for i in 0..8 { println!("{} => {} vs {}", i, bools[i], bools2[i]); } assert_eq!(bools, bools2); }