src/test/compile-fail/mutexguard-sync.rs

   1 // Copyright 2017 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // MutexGuard<Cell<i32>> must not be Sync, that would be unsound.
  12 use std::sync::Mutex;
  13 use std::cell::Cell;
  14
  15 fn test_sync<T: Sync>(_t: T) {}
  16
  17 fn main()
  18 {
  19     let m = Mutex::new(Cell::new(0i32));
  20     let guard = m.lock().unwrap();
  21     test_sync(guard); //~ ERROR the trait bound
  22 }