// Copyright 2013 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::Sync; struct NoSync; impl !Sync for NoSync {} enum Foo { A(NoSync) } fn bar(_: T) {} fn main() { let x = Foo::A(NoSync); bar(x); //~^ ERROR the trait `core::marker::Sync` is not implemented }