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 and the Sync trait for more details.
Implementors§
impl !Send for Args
impl !Send for ArgsOs
impl !Send for Arguments<'_>
impl !Send for LocalWaker
impl Send for core::ffi::c_str::Bytes<'_>
impl Send for BorrowedHandle<'_>
impl Send for HandleOrInvalid
impl Send for HandleOrNull
impl Send for OwnedHandle
impl Send for std::string::Drain<'_>
impl Send for Waker
impl<'a> Send for IoSlice<'a>
impl<'a> Send for IoSliceMut<'a>
impl<Dyn> Send for DynMetadata<Dyn>where
Dyn: ?Sized,
impl<T> !Send for *const Twhere
T: ?Sized,
impl<T> !Send for *mut Twhere
T: ?Sized,
impl<T> !Send for NonNull<T>where
T: ?Sized,
NonNull pointers are not Send because the data they reference may be aliased.
impl<T> Send for &T
impl<T> Send for ThinBox<T>
ThinBox<T> is Send if T is Send because the data is owned.
impl<T> Send for Cell<T>
impl<T> Send for RefCell<T>
impl<T> Send for std::collections::linked_list::Iter<'_, T>where
T: Sync,
impl<T> Send for std::collections::linked_list::IterMut<'_, T>where
T: Send,
impl<T> Send for NonZero<T>where
T: ZeroablePrimitive + Send,
impl<T> Send for ChunksExactMut<'_, T>where
T: Send,
impl<T> Send for ChunksMut<'_, T>where
T: Send,
impl<T> Send for std::slice::Iter<'_, T>where
T: Sync,
impl<T> Send for std::slice::IterMut<'_, T>where
T: Send,
impl<T> Send for RChunksExactMut<'_, T>where
T: Send,
impl<T> Send for RChunksMut<'_, T>where
T: Send,
impl<T> Send for AtomicPtr<T>
impl<T> Send for JoinHandle<T>
impl<T, A> !Send for Rc<T, A>
impl<T, A> !Send for UniqueRc<T, A>
impl<T, A> !Send for std::rc::Weak<T, A>
impl<T, A> Send for std::collections::linked_list::Cursor<'_, T, A>
impl<T, A> Send for std::collections::linked_list::CursorMut<'_, T, A>
impl<T, A> Send for LinkedList<T, A>
impl<T, A> Send for std::collections::vec_deque::Drain<'_, T, A>
impl<T, A> Send for Arc<T, A>
impl<T, A> Send for UniqueArc<T, A>
impl<T, A> Send for std::sync::Weak<T, A>
impl<T, A> Send for std::vec::Drain<'_, T, A>
impl<T, A> Send for std::vec::IntoIter<T, A>
impl<T: Send + ?Sized> Send for ReentrantLock<T>
impl<T: Send> Send for std::sync::mpmc::Receiver<T>
impl<T: Send> Send for std::sync::mpmc::Sender<T>
impl<T: Send> Send for std::sync::mpsc::Receiver<T>
impl<T: Send> Send for std::sync::mpsc::Sender<T>
impl<T: Send> Send for SyncSender<T>
impl<T: Send> Send for OnceLock<T>
impl<T: ?Sized + Send> Send for Mutex<T>
T must be Send for a Mutex to be Send because it is possible to acquire
the owned T from the Mutex via into_inner.
impl<T: ?Sized + Send> Send for RwLock<T>
impl<T: ?Sized> !Send for MappedMutexGuard<'_, T>
impl<T: ?Sized> !Send for MappedRwLockReadGuard<'_, T>
impl<T: ?Sized> !Send for MappedRwLockWriteGuard<'_, T>
impl<T: ?Sized> !Send for MutexGuard<'_, T>
A MutexGuard is not Send to maximize platform portablity.
On platforms that use POSIX threads (commonly referred to as pthreads) there is a requirement to
release mutex locks on the same thread they were acquired.
For this reason, MutexGuard must not implement Send to prevent it being dropped from
another thread.