expose sync::{Arc,Weak}

Signed-off-by: Yoshua Wuyts <yoshuawuyts@gmail.com>

src/sync/mod.rs

@@ -29,6 +29,9 @@
 //! # }) }
 //! ```
 
+#[doc(inline)]
+pub use std::sync::{Arc, Weak};
+
 pub use mutex::{Mutex, MutexGuard};
 pub use rwlock::{RwLock, RwLockReadGuard, RwLockWriteGuard};