pub unsafe auto trait Send { }Expand description
Types that can be transferred across thread boundaries.
This trait is automatically implemented when the compiler determines it’s appropriate.
An example of a non-Send type is the reference-counting pointer
rc::Rc. If two threads attempt to clone Rcs that point to the same
reference-counted value, they might try to update the reference count at the
same time, which is undefined behavior because Rc doesn’t use atomic
operations. Its cousin sync::Arc does use atomic operations (incurring
some overhead) and thus is Send.
See the Nomicon for more details.
Implementations on Foreign Types
impl Send for Argument
impl Send for FormatSpec
impl Send for Alignment
impl Send for Count
impl<T> Send for SyncOnceCell<T> where
T: Send,
impl<T> Send for Mutex<T> where
T: Send + ?Sized,
impl<'a> Send for IoSliceMut<'a>
impl Send for Once
impl !Send for ArgsOs
impl<'_, T> !Send for MutexGuard<'_, T> where
T: ?Sized,
impl<'_, T> !Send for RwLockReadGuard<'_, T> where
T: ?Sized,
impl !Send for Args
impl<T> Send for Receiver<T> where
T: Send,
impl<'_, T> !Send for RwLockWriteGuard<'_, T> where
T: ?Sized,
impl<T> Send for Sender<T> where
T: Send,
impl<'a> Send for IoSlice<'a>
impl<T> Send for RwLock<T> where
T: Send + ?Sized,
impl<T> Send for SyncSender<T> where
T: Send,
impl<T> Send for JoinHandle<T>
impl Send for Waker
impl<'_, T> Send for &'_ T where
T: Sync + ?Sized,
impl<Dyn> Send for DynMetadata<Dyn> where
Dyn: ?Sized,
impl<T> Send for AtomicPtr<T>
impl<'_, T> Send for Iter<'_, T> where
T: Sync,
impl<T> Send for Cell<T> where
T: Send + ?Sized,
impl<T> !Send for *const T where
T: ?Sized,
impl<T> !Send for NonNull<T> where
T: ?Sized,
NonNull pointers are not Send because the data they reference may be aliased.