#![feature(box_syntax)] use std::sync::mpsc::channel; pub fn main() { let (tx, rx) = channel::>(); tx.send(box 100).unwrap(); let v = rx.recv().unwrap(); assert_eq!(v, box 100); tx.send(box 101).unwrap(); tx.send(box 102).unwrap(); assert_eq!(rx.recv().unwrap(), box 101); assert_eq!(rx.recv().unwrap(), box 102); }