| // Copyright 2014 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // Verify that UnsafeCell is *always* !Sync regardless if `T` is sync. |
| |
| #![feature(optin_builtin_traits)] |
| |
| use std::cell::UnsafeCell; |
| use std::marker::Sync; |
| |
| struct MySync<T> { |
| u: UnsafeCell<T> |
| } |
| |
| struct NoSync; |
| impl !Sync for NoSync {} |
| |
| fn test<T: Sync>(s: T) {} |
| |
| fn main() { |
| let us = UnsafeCell::new(MySync{u: UnsafeCell::new(0)}); |
| test(us); |
| //~^ ERROR `std::cell::UnsafeCell<MySync<{integer}>>` cannot be shared between threads safely |
| |
| let uns = UnsafeCell::new(NoSync); |
| test(uns); |
| //~^ ERROR `std::cell::UnsafeCell<NoSync>` cannot be shared between threads safely [E0277] |
| |
| let ms = MySync{u: uns}; |
| test(ms); |
| //~^ ERROR `std::cell::UnsafeCell<NoSync>` cannot be shared between threads safely [E0277] |
| |
| test(NoSync); |
| //~^ ERROR `NoSync` cannot be shared between threads safely [E0277] |
| } |