Trait std::marker::Sync 1.0.0[−][src]
#[lang = "sync"]pub unsafe auto trait Sync { }
Types for which it is safe to share references between threads.
This trait is automatically implemented when the compiler determines it's appropriate.
The precise definition is: a type T is Sync if and only if &T is
Send. In other words, if there is no possibility of
undefined behavior (including data races) when passing
&T references between threads.
As one would expect, primitive types like u8 and f64
are all Sync, and so are simple aggregate types containing them,
like tuples, structs and enums. More examples of basic Sync
types include "immutable" types like &T, and those with simple
inherited mutability, such as Box<T>, Vec<T> and
most other collection types. (Generic parameters need to be Sync
for their container to be Sync.)
A somewhat surprising consequence of the definition is that &mut T
is Sync (if T is Sync) even though it seems like that might
provide unsynchronized mutation. The trick is that a mutable
reference behind a shared reference (that is, & &mut T)
becomes read-only, as if it were a & &T. Hence there is no risk
of a data race.
Types that are not Sync are those that have "interior
mutability" in a non-thread-safe form, such as cell::Cell
and cell::RefCell. These types allow for mutation of
their contents even through an immutable, shared reference. For
example the set method on Cell<T> takes &self, so it requires
only a shared reference &Cell<T>. The method performs no
synchronization, thus Cell cannot be Sync.
Another example of a non-Sync type is the reference-counting
pointer rc::Rc. Given any reference &Rc<T>, you can clone
a new Rc<T>, modifying the reference counts in a non-atomic way.
For cases when one does need thread-safe interior mutability,
Rust provides atomic data types, as well as explicit locking via
sync::Mutex and sync::RwLock. These types
ensure that any mutation cannot cause data races, hence the types
are Sync. Likewise, sync::Arc provides a thread-safe
analogue of Rc.
Any types with interior mutability must also use the
cell::UnsafeCell wrapper around the value(s) which
can be mutated through a shared reference. Failing to doing this is
undefined behavior. For example, transmute-ing
from &T to &mut T is invalid.
See the Nomicon for more
details about Sync.
Implementations on Foreign Types
impl Sync for Argument
impl Sync for Argumentimpl Sync for FormatSpec
impl Sync for FormatSpecimpl Sync for Alignment
impl Sync for Alignmentimpl Sync for Count
impl Sync for Countimpl Sync for Position
impl Sync for Positionimpl Sync for __m64
impl Sync for __m64impl Sync for __m128
impl Sync for __m128impl Sync for __m256d
impl Sync for __m256dimpl Sync for __m128d
impl Sync for __m128dimpl Sync for __m256
impl Sync for __m256impl Sync for CpuidResult
impl Sync for CpuidResultimpl Sync for __m256i
impl Sync for __m256iimpl Sync for __m128i
impl Sync for __m128iImplementors
impl Sync for AtomicUsizeimpl<T> !Sync for NonNull<T> where
T: ?Sized,impl<'a, T> Sync for std::slice::IterMut<'a, T> where
T: Sync,impl<'a, T> Sync for std::slice::Iter<'a, T> where
T: Sync,impl Sync for Wakerimpl Sync for AtomicIsizeimpl<T> Sync for AtomicPtr<T>impl<T> !Sync for UnsafeCell<T> where
T: ?Sized,impl<T> !Sync for RefCell<T> where
T: ?Sized,impl<T> !Sync for Cell<T> where
T: ?Sized,impl !Sync for LocalWakerimpl Sync for AtomicI64impl Sync for AtomicU64impl Sync for AtomicBoolimpl Sync for AtomicI16impl<T> !Sync for *const T where
T: ?Sized,impl Sync for AtomicU16impl Sync for AtomicU32impl Sync for AtomicU8impl Sync for AtomicI32impl<T> !Sync for *mut T where
T: ?Sized,impl Sync for AtomicI8impl<'a, T> Sync for std::collections::linked_list::IterMut<'a, T> where
T: Sync,impl<T> !Sync for Rc<T> where
T: ?Sized,impl<T> Sync for Arc<T> where
T: Send + Sync + ?Sized,impl<'a, T> Sync for std::collections::linked_list::Iter<'a, T> where
T: Sync,impl<T> Sync for LinkedList<T> where
T: Sync,impl<T> Sync for std::vec::IntoIter<T> where
T: Sync,impl<'a, T> Sync for std::vec::Drain<'a, T> where
T: Sync,impl<T> !Sync for std::rc::Weak<T> where
T: ?Sized,impl<'a> Sync for std::string::Drain<'a>impl<'a, T> Sync for std::collections::vec_deque::Drain<'a, T> where
T: Sync,impl<T> Sync for std::sync::Weak<T> where
T: Send + Sync + ?Sized,impl<T> Sync for JoinHandle<T>impl !Sync for Argsimpl !Sync for ArgsOsimpl<T> !Sync for Receiver<T>impl<T> !Sync for Sender<T>impl<T: ?Sized + Send> Sync for Mutex<T>impl<'a, T: ?Sized + Sync> Sync for MutexGuard<'a, T>impl Sync for std::sync::Onceimpl<T: ?Sized + Send + Sync> Sync for RwLock<T>impl<'a, T: ?Sized + Sync> Sync for RwLockReadGuard<'a, T>impl<'a, T: ?Sized + Sync> Sync for RwLockWriteGuard<'a, T>
Auto implementors
impl Sync for isizeimpl Sync for i8impl Sync for i16impl Sync for i32impl Sync for i64impl Sync for i128impl Sync for usizeimpl Sync for u8impl Sync for u16impl Sync for u32impl Sync for u64impl Sync for u128impl Sync for f32impl Sync for f64impl Sync for charimpl Sync for strimpl Sync for strimpl Sync for TypeIdimpl Sync for BorrowErrorimpl Sync for BorrowMutErrorimpl<'b, T> !Sync for Ref<'b, T>impl<'b, T> !Sync for RefMut<'b, T>impl Sync for std::cmp::Orderingimpl<T> Sync for Reverse<T> where
T: Sync,impl<H> Sync for BuildHasherDefault<H> where
H: Sync,impl Sync for SipHasherimpl<T> Sync for Rev<T> where
T: Sync,impl<I> Sync for Cloned<I> where
I: Sync,impl<I> Sync for Cycle<I> where
I: Sync,impl<I> Sync for StepBy<I> where
I: Sync,impl<A, B> Sync for std::iter::Chain<A, B> where
A: Sync,
B: Sync,impl<A, B> Sync for Zip<A, B> where
A: Sync,
B: Sync,impl<I, F> Sync for Map<I, F> where
F: Sync,
I: Sync,impl<I, P> Sync for Filter<I, P> where
I: Sync,
P: Sync,impl<I, F> Sync for FilterMap<I, F> where
F: Sync,
I: Sync,impl<I> Sync for Enumerate<I> where
I: Sync,impl<I> Sync for Peekable<I> where
I: Sync,
<I as Iterator>::Item: Sync,impl<I, P> Sync for SkipWhile<I, P> where
I: Sync,
P: Sync,impl<I, P> Sync for TakeWhile<I, P> where
I: Sync,
P: Sync,impl<I> Sync for Skip<I> where
I: Sync,impl<I> Sync for std::iter::Take<I> where
I: Sync,impl<I, St, F> Sync for Scan<I, St, F> where
F: Sync,
I: Sync,
St: Sync,impl<I, U, F> Sync for FlatMap<I, U, F> where
F: Sync,
I: Sync,
<U as IntoIterator>::IntoIter: Sync,impl<I> Sync for Flatten<I> where
I: Sync,
<<I as Iterator>::Item as IntoIterator>::IntoIter: Sync,impl<I> Sync for Fuse<I> where
I: Sync,impl<I, F> Sync for Inspect<I, F> where
F: Sync,
I: Sync,impl<T> Sync for std::iter::Empty<T> where
T: Sync,impl<A> Sync for std::iter::Repeat<A> where
A: Sync,impl<F> Sync for RepeatWith<F> where
F: Sync,impl<T> Sync for std::iter::Once<T> where
T: Sync,impl<T: ?Sized> Sync for PhantomData<T> where
T: Sync,impl Sync for Pinnedimpl<T> Sync for Discriminant<T>impl<T> Sync for ManuallyDrop<T> where
T: Sync,impl<'a, T: ?Sized> Sync for PinMut<'a, T> where
T: Sync,impl<T> Sync for Bound<T> where
T: Sync,impl<Y, R> Sync for GeneratorState<Y, R> where
R: Sync,
Y: Sync,impl<Idx> Sync for RangeToInclusive<Idx> where
Idx: Sync,impl<Idx> Sync for RangeTo<Idx> where
Idx: Sync,impl Sync for RangeFullimpl<Idx> Sync for RangeFrom<Idx> where
Idx: Sync,impl<Idx> Sync for RangeInclusive<Idx> where
Idx: Sync,impl<Idx> Sync for std::ops::Range<Idx> where
Idx: Sync,impl !Sync for TraitObjectimpl<T, E> Sync for Result<T, E> where
E: Sync,
T: Sync,impl<'a, T> Sync for std::result::Iter<'a, T> where
T: Sync,impl<'a, T> Sync for std::result::IterMut<'a, T> where
T: Sync,impl<T> Sync for std::result::IntoIter<T> where
T: Sync,impl<T> Sync for Option<T> where
T: Sync,impl<'a, A> Sync for std::option::Iter<'a, A> where
A: Sync,impl<'a, A> Sync for std::option::IterMut<'a, A> where
A: Sync,impl<A> Sync for std::option::IntoIter<A> where
A: Sync,impl Sync for NoneErrorimpl<T: ?Sized> Sync for Box<T> where
T: Sync,impl<T: ?Sized> Sync for PinBox<T> where
T: Sync,impl<'a, B: ?Sized> Sync for Cow<'a, B> where
B: Sync,
<B as ToOwned>::Owned: Sync,impl<'a> !Sync for Formatter<'a>impl<'a, 'b> !Sync for DebugMap<'a, 'b>impl<'a, 'b> !Sync for DebugList<'a, 'b>impl<'a, 'b> !Sync for DebugTuple<'a, 'b>impl<'a, 'b> !Sync for DebugSet<'a, 'b>impl Sync for std::fmt::Errorimpl<'a> !Sync for Arguments<'a>impl<'a, 'b> !Sync for DebugStruct<'a, 'b>impl Sync for std::fmt::Alignmentimpl<'a, T, P> Sync for std::slice::RSplitN<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T> Sync for ExactChunksMut<'a, T> where
T: Sync,impl<'a, T> Sync for Windows<'a, T> where
T: Sync,impl<'a, T> Sync for ExactChunks<'a, T> where
T: Sync,impl<'a, T> Sync for Chunks<'a, T> where
T: Sync,impl<'a, T, P> Sync for std::slice::SplitN<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T, P> Sync for std::slice::Split<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T> Sync for ChunksMut<'a, T> where
T: Sync,impl<'a, T, P> Sync for RSplitNMut<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T, P> Sync for SplitMut<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T, P> Sync for RSplitMut<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T, P> Sync for SplitNMut<'a, T, P> where
P: Sync,
T: Sync,impl<'a, T, P> Sync for std::slice::RSplit<'a, T, P> where
P: Sync,
T: Sync,impl<'a> Sync for CharIndices<'a>impl<'a, P> Sync for RSplitTerminator<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a, P> Sync for std::str::RSplitN<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl Sync for ParseBoolErrorimpl<'a, P> Sync for RMatchIndices<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a> Sync for EncodeUtf16<'a>impl<'a, P> Sync for MatchIndices<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a, P> Sync for SplitTerminator<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a, P> Sync for std::str::SplitN<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a> Sync for std::str::Chars<'a>impl<'a, P> Sync for std::str::Split<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a> Sync for LinesAny<'a>impl<'a> Sync for SplitAsciiWhitespace<'a>impl Sync for SearchStepimpl<'a> Sync for CharSearcher<'a>impl<'a, 'b> Sync for CharSliceSearcher<'a, 'b>impl<'a, F> Sync for CharPredicateSearcher<'a, F> where
F: Sync,impl<'a, 'b> Sync for StrSearcher<'a, 'b>impl<'a, P> Sync for RMatches<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a> Sync for std::str::Bytes<'a>impl<'a> Sync for std::str::Lines<'a>impl<'a, P> Sync for Matches<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl<'a> Sync for SplitWhitespace<'a>impl<'a, P> Sync for std::str::RSplit<'a, P> where
<P as Pattern<'a>>::Searcher: Sync,impl Sync for Utf8Errorimpl Sync for Stringimpl Sync for FromUtf8Errorimpl Sync for FromUtf16Errorimpl Sync for ParseErrorimpl<T> Sync for Vec<T> where
T: Sync,impl<'a, I> Sync for Splice<'a, I> where
I: Sync,
<I as Iterator>::Item: Sync,impl<'a, T, F> Sync for std::vec::DrainFilter<'a, T, F> where
F: Sync,
T: Sync,impl Sync for EscapeUnicodeimpl Sync for std::char::EscapeDefaultimpl Sync for EscapeDebugimpl Sync for ToLowercaseimpl Sync for ToUppercaseimpl Sync for ParseCharErrorimpl Sync for DecodeUtf16Errorimpl Sync for UnicodeVersionimpl<I> Sync for DecodeUtf8<I> where
I: Sync,impl<I> Sync for DecodeUtf16<I> where
I: Sync,impl Sync for CharTryFromErrorimpl Sync for InvalidSequenceimpl<T> Sync for LocalKey<T>impl Sync for AccessErrorimpl Sync for Builderimpl Sync for ThreadIdimpl Sync for Threadimpl Sync for std::ascii::EscapeDefaultimpl<T> Sync for BinaryHeap<T> where
T: Sync,impl<K, V> Sync for BTreeMap<K, V> where
K: Sync,
V: Sync,impl<T> Sync for BTreeSet<T> where
T: Sync,impl<T> Sync for VecDeque<T> where
T: Sync,impl<'a, T> Sync for PeekMut<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::binary_heap::Iter<'a, T> where
T: Sync,impl<T> Sync for std::collections::binary_heap::IntoIter<T> where
T: Sync,impl<'a, T> Sync for std::collections::binary_heap::Drain<'a, T> where
T: Sync,impl<'a, K, V> Sync for std::collections::btree_map::Iter<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::VacantEntry<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::Values<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::Range<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::Entry<'a, K, V> where
K: Sync,
V: Sync,impl<K, V> Sync for std::collections::btree_map::IntoIter<K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::IterMut<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::ValuesMut<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::OccupiedEntry<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for RangeMut<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::btree_map::Keys<'a, K, V> where
K: Sync,
V: Sync,impl<'a, T> Sync for std::collections::btree_set::Iter<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::btree_set::SymmetricDifference<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::btree_set::Intersection<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::btree_set::Range<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::btree_set::Union<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::btree_set::Difference<'a, T> where
T: Sync,impl<T> Sync for std::collections::btree_set::IntoIter<T> where
T: Sync,impl<T> Sync for std::collections::linked_list::IntoIter<T> where
T: Sync,impl<'a, T, F> !Sync for std::collections::linked_list::DrainFilter<'a, T, F>impl<'a, T> Sync for std::collections::vec_deque::Iter<'a, T> where
T: Sync,impl<'a, T> Sync for std::collections::vec_deque::IterMut<'a, T> where
T: Sync,impl<T> Sync for std::collections::vec_deque::IntoIter<T> where
T: Sync,impl Sync for CollectionAllocErrimpl<K, V, S> Sync for HashMap<K, V, S> where
K: Sync,
S: Sync,
V: Sync,impl<T, S> Sync for HashSet<T, S> where
S: Sync,
T: Sync,impl<'a, K, V> Sync for std::collections::hash_map::Iter<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::hash_map::IterMut<'a, K, V> where
K: Sync,
V: Sync,impl<K, V> Sync for std::collections::hash_map::IntoIter<K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::hash_map::Keys<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::hash_map::Values<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::hash_map::Drain<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> Sync for std::collections::hash_map::ValuesMut<'a, K, V> where
K: Sync,
V: Sync,impl<'a, K, V> !Sync for std::collections::hash_map::OccupiedEntry<'a, K, V>impl<'a, K, V> !Sync for std::collections::hash_map::VacantEntry<'a, K, V>impl Sync for RandomStateimpl Sync for DefaultHasherimpl<'a, K, V> !Sync for std::collections::hash_map::Entry<'a, K, V>impl<'a, K> Sync for std::collections::hash_set::Iter<'a, K> where
K: Sync,impl<K> Sync for std::collections::hash_set::IntoIter<K> where
K: Sync,impl<'a, K> Sync for std::collections::hash_set::Drain<'a, K> where
K: Sync,impl<'a, T, S> Sync for std::collections::hash_set::Intersection<'a, T, S> where
S: Sync,
T: Sync,impl<'a, T, S> Sync for std::collections::hash_set::Difference<'a, T, S> where
S: Sync,
T: Sync,impl<'a, T, S> Sync for std::collections::hash_set::SymmetricDifference<'a, T, S> where
S: Sync,
T: Sync,impl<'a, T, S> Sync for std::collections::hash_set::Union<'a, T, S> where
S: Sync,
T: Sync,impl !Sync for Varsimpl !Sync for VarsOsimpl<'a> Sync for SplitPaths<'a>impl Sync for JoinPathsErrorimpl Sync for VarErrorimpl Sync for CStringimpl Sync for CStrimpl Sync for NulErrorimpl Sync for IntoStringErrorimpl Sync for FromBytesWithNulErrorimpl Sync for OsStringimpl Sync for OsStrimpl Sync for Fileimpl Sync for Metadataimpl Sync for ReadDirimpl Sync for DirEntryimpl Sync for OpenOptionsimpl Sync for Permissionsimpl Sync for FileTypeimpl Sync for DirBuilderimpl<R> Sync for BufReader<R> where
R: Sync,impl<W> Sync for BufWriter<W> where
W: Sync,impl<W> Sync for LineWriter<W> where
W: Sync,impl<W> Sync for IntoInnerError<W> where
W: Sync,impl<T> Sync for Cursor<T> where
T: Sync,impl Sync for std::io::Errorimpl Sync for Sinkimpl Sync for std::io::Emptyimpl Sync for std::io::Repeatimpl Sync for Stdinimpl Sync for Stdoutimpl Sync for Stderrimpl<'a> Sync for StdoutLock<'a>impl<'a> Sync for StderrLock<'a>impl<'a> Sync for StdinLock<'a>impl Sync for Initializerimpl<T, U> Sync for std::io::Chain<T, U> where
T: Sync,
U: Sync,impl<T> Sync for std::io::Take<T> where
T: Sync,impl<R> Sync for std::io::Bytes<R> where
R: Sync,impl<R> Sync for std::io::Chars<R> where
R: Sync,impl<B> Sync for std::io::Split<B> where
B: Sync,impl<B> Sync for std::io::Lines<B> where
B: Sync,impl Sync for ErrorKindimpl Sync for SeekFromimpl Sync for CharsErrorimpl Sync for Ipv4Addrimpl Sync for Ipv6Addrimpl Sync for SocketAddrV4impl Sync for SocketAddrV6impl Sync for TcpStreamimpl Sync for TcpListenerimpl<'a> Sync for std::net::Incoming<'a>impl Sync for UdpSocketimpl Sync for AddrParseErrorimpl Sync for IpAddrimpl Sync for Ipv6MulticastScopeimpl Sync for std::net::SocketAddrimpl Sync for Shutdownimpl Sync for FpCategoryimpl Sync for ParseIntErrorimpl Sync for ParseFloatErrorimpl Sync for TryFromIntErrorimpl<T> Sync for Wrapping<T> where
T: Sync,impl Sync for NonZeroU8impl Sync for NonZeroU16impl Sync for NonZeroU32impl Sync for NonZeroU64impl Sync for NonZeroU128impl Sync for NonZeroUsizeimpl Sync for std::os::unix::net::SocketAddrimpl Sync for UnixStreamimpl Sync for UnixListenerimpl<'a> Sync for std::os::unix::net::Incoming<'a>impl Sync for UnixDatagramimpl<'a> Sync for EncodeWide<'a>impl Sync for statimpl Sync for c_voidimpl<'a> !Sync for PanicInfo<'a>impl<'a> Sync for Location<'a>impl<T> Sync for AssertUnwindSafe<T> where
T: Sync,impl<'a> Sync for PrefixComponent<'a>impl<'a> Sync for Components<'a>impl<'a> Sync for std::path::Iter<'a>impl<'a> Sync for Ancestors<'a>impl Sync for PathBufimpl Sync for Pathimpl Sync for StripPrefixErrorimpl<'a> Sync for Display<'a>impl<'a> Sync for Prefix<'a>impl<'a> Sync for Component<'a>impl Sync for Childimpl Sync for ChildStdinimpl Sync for ChildStdoutimpl Sync for ChildStderrimpl !Sync for Commandimpl Sync for Outputimpl Sync for Stdioimpl Sync for ExitStatusimpl Sync for ExitCodeimpl Sync for std::sync::atomic::Orderingimpl Sync for Barrierimpl Sync for BarrierWaitResultimpl Sync for Condvarimpl Sync for WaitTimeoutResultimpl Sync for OnceStateimpl<T> Sync for PoisonError<T> where
T: Sync,impl<T> Sync for TryLockError<T> where
T: Sync,impl !Sync for Selectimpl<'rx, T> !Sync for Handle<'rx, T>impl<'a, T> !Sync for std::sync::mpsc::Iter<'a, T>impl<'a, T> !Sync for TryIter<'a, T>impl<T> !Sync for std::sync::mpsc::IntoIter<T>impl<T> Sync for SyncSender<T> where
T: Send,impl<T> Sync for SendError<T> where
T: Sync,impl Sync for RecvErrorimpl Sync for TryRecvErrorimpl Sync for RecvTimeoutErrorimpl<T> Sync for TrySendError<T> where
T: Sync,impl Sync for Durationimpl Sync for Instantimpl Sync for SystemTimeimpl Sync for SystemTimeErrorimpl !Sync for SpawnLocalObjErrorimpl Sync for SpawnErrorKindimpl<T> Sync for Poll<T> where
T: Sync,impl<'a> !Sync for Context<'a>impl !Sync for SpawnObjErrorimpl<'a, T> !Sync for LocalFutureObj<'a, T>impl<'a, T> !Sync for FutureObj<'a, T>impl Sync for Globalimpl Sync for CannotReallocInPlaceimpl Sync for AllocErrimpl Sync for Layoutimpl Sync for LayoutErrimpl !Sync for Excessimpl Sync for System