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 Rc
s 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.
Implementors§
impl !Send for Args
impl !Send for ArgsOs
impl Send for Waker
impl Send for alloc::string::Drain<'_>
impl<'a> Send for IoSlice<'a>
impl<'a> Send for IoSliceMut<'a>
impl<'a, 'b, K, Q, V, S, A> Send for OccupiedEntryRef<'a, 'b, K, Q, V, S, A>where K: Send, Q: Sync + ?Sized, V: Send, S: Send, A: Send + Allocator + Clone,
impl<Dyn> Send for DynMetadata<Dyn>where Dyn: ?Sized,
impl<K, V> Send for IterMut<'_, K, V>where K: Send, V: Send,
impl<K, V, S, A> Send for OccupiedEntry<'_, K, V, S, A>where K: Send, V: Send, S: Send, A: Send + Allocator + Clone,
impl<K, V, S, A> Send for RawOccupiedEntryMut<'_, K, V, S, A>where K: Send, V: Send, S: Send, A: Send + Allocator + Clone,
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 Rc<T>where T: ?Sized,
impl<T> !Send for alloc::rc::Weak<T>where T: ?Sized,
impl<T> !Send for MutexGuard<'_, T>where T: ?Sized,
impl<T> !Send for RwLockReadGuard<'_, T>where T: ?Sized,
impl<T> !Send for RwLockWriteGuard<'_, T>where T: ?Sized,
impl<T> Send for &Twhere T: Sync + ?Sized,
impl<T> Send for Cell<T>where T: Send + ?Sized,
impl<T> Send for RefCell<T>where T: Send + ?Sized,
impl<T> Send for ChunksExactMut<'_, T>where T: Send,
impl<T> Send for ChunksMut<'_, T>where T: Send,
impl<T> Send for wasmtime_environ::__core::slice::Iter<'_, T>where T: Sync,
impl<T> Send for wasmtime_environ::__core::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 ThinBox<T>where T: Send + ?Sized,
ThinBox<T>
is Send
if T
is Send
because the data is owned.