// Copyright 2015 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #![feature(optin_builtin_traits)] use std::marker::Send; pub struct WaitToken; impl !Send for WaitToken {} pub struct Test(T); unsafe impl Send for Test {} pub fn spawn(_: F) -> () where F: FnOnce(), F: Send + 'static {} fn main() { let wt = Test(WaitToken); spawn(move || { let x = wt; println!("Hello, World!"); }); }