Trait std::marker::Unpin
pub auto trait Unpin { }
Types that can be safely moved after being pinned.
Rust itself has no notion of immovable types, and considers moves (e.g., through assignment or mem::replace
) to always be safe.
The Pin
type is used instead to prevent moves through the type system. Pointers P<T>
wrapped in the Pin<P<T>>
wrapper can’t be moved out of. See the pin
module documentation for more information on pinning.
Implementing the Unpin
trait for T
lifts the restrictions of pinning off the type, which then allows moving T
out of Pin<P<T>>
with functions such as mem::replace
.
Unpin
has no consequence at all for non-pinned data. In particular, mem::replace
happily moves !Unpin
data (it works for any &mut T
, not just when T: Unpin
). However, you cannot use mem::replace
on data wrapped inside a Pin<P<T>>
because you cannot get the &mut T
you need for that, and that is what makes this system work.
So this, for example, can only be done on types implementing Unpin
:
use std::mem; use std::pin::Pin; let mut string = "this".to_string(); let mut pinned_string = Pin::new(&mut string); // We need a mutable reference to call `mem::replace`. // We can obtain such a reference by (implicitly) invoking `Pin::deref_mut`, // but that is only possible because `String` implements `Unpin`. mem::replace(&mut *pinned_string, "other".to_string());
This trait is automatically implemented for almost every type.
Implementations on Foreign Types
impl Unpin for Argument
impl Unpin for FormatSpec
impl Unpin for Alignment
impl Unpin for Count
Implementors
impl !Unpin for PhantomPinned
impl Unpin for Waker
impl<F> Unpin for PollFn<F>
impl<I> Unpin for FromIter<I>
impl<T> Unpin for Pending<T>
impl<T> Unpin for Ready<T>
Auto implementors
impl Unpin for BacktraceStatus
impl Unpin for std::cmp::Ordering
impl Unpin for TryReserveErrorKind
impl Unpin for Infallible
impl Unpin for VarError
impl Unpin for c_void
impl Unpin for std::fmt::Alignment
impl Unpin for ErrorKind
impl Unpin for SeekFrom
impl Unpin for IpAddr
impl Unpin for Ipv6MulticastScope
impl Unpin for Shutdown
impl Unpin for std::net::SocketAddr
impl Unpin for FpCategory
impl Unpin for IntErrorKind
impl Unpin for AncillaryError
impl Unpin for SearchStep
impl Unpin for std::sync::atomic::Ordering
impl Unpin for RecvTimeoutError
impl Unpin for TryRecvError
impl Unpin for bool
impl Unpin for char
impl Unpin for f32
impl Unpin for f64
impl Unpin for i8
impl Unpin for i16
impl Unpin for i32
impl Unpin for i64
impl Unpin for i128
impl Unpin for isize
impl Unpin for [u8]
impl Unpin for str
impl Unpin for u8
impl Unpin for u16
impl Unpin for u32
impl Unpin for u64
impl Unpin for u128
impl Unpin for usize
impl Unpin for AllocError
impl Unpin for Global
impl Unpin for Layout
impl Unpin for LayoutError
impl Unpin for System
impl Unpin for TypeId
impl Unpin for TryFromSliceError
impl Unpin for std::ascii::EscapeDefault
impl Unpin for Backtrace
impl Unpin for BacktraceFrame
impl Unpin for BorrowError
impl Unpin for BorrowMutError
impl Unpin for CharTryFromError
impl Unpin for DecodeUtf16Error
impl Unpin for std::char::EscapeDebug
impl Unpin for std::char::EscapeDefault
impl Unpin for std::char::EscapeUnicode
impl Unpin for ParseCharError
impl Unpin for ToLowercase
impl Unpin for ToUppercase
impl Unpin for DefaultHasher
impl Unpin for RandomState
impl Unpin for TryReserveError
impl Unpin for Args
impl Unpin for ArgsOs
impl Unpin for JoinPathsError
impl Unpin for Vars
impl Unpin for VarsOs
impl Unpin for CStr
impl Unpin for CString
impl Unpin for FromBytesWithNulError
impl Unpin for FromVecWithNulError
impl Unpin for IntoStringError
impl Unpin for NulError
impl Unpin for OsStr
impl Unpin for OsString
impl Unpin for std::fmt::Error
impl Unpin for DirBuilder
impl Unpin for DirEntry
impl Unpin for File
impl Unpin for FileType
impl Unpin for Metadata
impl Unpin for OpenOptions
impl Unpin for Permissions
impl Unpin for ReadDir
impl Unpin for SipHasher
impl Unpin for std::io::Empty
impl Unpin for std::io::Error
impl Unpin for Initializer
impl Unpin for std::io::Repeat
impl Unpin for Sink
impl Unpin for Stderr
impl Unpin for Stdin
impl Unpin for Stdout
impl Unpin for WriterPanicked
impl Unpin for AddrParseError
impl Unpin for Ipv4Addr
impl Unpin for Ipv6Addr
impl Unpin for SocketAddrV4
impl Unpin for SocketAddrV6
impl Unpin for TcpListener
impl Unpin for TcpStream
impl Unpin for UdpSocket
impl Unpin for NonZeroI8
impl Unpin for NonZeroI16
impl Unpin for NonZeroI32
impl Unpin for NonZeroI64
impl Unpin for NonZeroI128
impl Unpin for NonZeroIsize
impl Unpin for NonZeroU8
impl Unpin for NonZeroU16
impl Unpin for NonZeroU32
impl Unpin for NonZeroU64
impl Unpin for NonZeroU128
impl Unpin for NonZeroUsize
impl Unpin for ParseFloatError
impl Unpin for ParseIntError
impl Unpin for TryFromIntError
impl Unpin for RangeFull
impl Unpin for PidFd
impl Unpin for stat
impl Unpin for OwnedFd
impl Unpin for std::os::unix::net::SocketAddr
impl Unpin for SocketCred
impl Unpin for UCred
impl Unpin for UnixDatagram
impl Unpin for UnixListener
impl Unpin for UnixStream
impl Unpin for HandleOrInvalid
impl Unpin for OwnedHandle
impl Unpin for OwnedSocket
impl Unpin for Path
impl Unpin for PathBuf
impl Unpin for StripPrefixError
impl Unpin for Child
impl Unpin for ChildStderr
impl Unpin for ChildStdin
impl Unpin for ChildStdout
impl Unpin for Command
impl Unpin for ExitCode
impl Unpin for ExitStatus
impl Unpin for ExitStatusError
impl Unpin for Output
impl Unpin for Stdio
impl Unpin for ParseBoolError
impl Unpin for Utf8Error
impl Unpin for FromUtf8Error
impl Unpin for FromUtf16Error
impl Unpin for String
impl Unpin for AtomicBool
impl Unpin for AtomicI8
impl Unpin for AtomicI16
impl Unpin for AtomicI32
impl Unpin for AtomicI64
impl Unpin for AtomicIsize
impl Unpin for AtomicU8
impl Unpin for AtomicU16
impl Unpin for AtomicU32
impl Unpin for AtomicU64
impl Unpin for AtomicUsize
impl Unpin for RecvError
impl Unpin for Barrier
impl Unpin for BarrierWaitResult
impl Unpin for Condvar
impl Unpin for std::sync::Once
impl Unpin for OnceState
impl Unpin for WaitTimeoutResult
impl Unpin for RawWaker
impl Unpin for RawWakerVTable
impl Unpin for AccessError
impl Unpin for Builder
impl Unpin for Thread
impl Unpin for ThreadId
impl Unpin for Duration
impl Unpin for Instant
impl Unpin for SystemTime
impl Unpin for SystemTimeError
impl<'a> Unpin for AncillaryData<'a>
impl<'a> Unpin for Component<'a>
impl<'a> Unpin for Prefix<'a>
impl<'a> Unpin for SplitPaths<'a>
impl<'a> Unpin for std::error::Chain<'a>
impl<'a> Unpin for Arguments<'a>
impl<'a> Unpin for Formatter<'a>
impl<'a> Unpin for IoSlice<'a>
impl<'a> Unpin for IoSliceMut<'a>
impl<'a> Unpin for StderrLock<'a>
impl<'a> Unpin for StdinLock<'a>
impl<'a> Unpin for StdoutLock<'a>
impl<'a> Unpin for std::net::Incoming<'a>
impl<'a> Unpin for std::os::unix::net::Incoming<'a>
impl<'a> Unpin for Messages<'a>
impl<'a> Unpin for ScmCredentials<'a>
impl<'a> Unpin for ScmRights<'a>
impl<'a> Unpin for SocketAncillary<'a>
impl<'a> Unpin for EncodeWide<'a>
impl<'a> Unpin for Location<'a>
impl<'a> Unpin for PanicInfo<'a>
impl<'a> Unpin for Ancestors<'a>
impl<'a> Unpin for Components<'a>
impl<'a> Unpin for Display<'a>
impl<'a> Unpin for std::path::Iter<'a>
impl<'a> Unpin for PrefixComponent<'a>
impl<'a> Unpin for CommandArgs<'a>
impl<'a> Unpin for CommandEnvs<'a>
impl<'a> Unpin for CharSearcher<'a>
impl<'a> Unpin for std::str::Bytes<'a>
impl<'a> Unpin for CharIndices<'a>
impl<'a> Unpin for Chars<'a>
impl<'a> Unpin for EncodeUtf16<'a>
impl<'a> Unpin for std::str::EscapeDebug<'a>
impl<'a> Unpin for std::str::EscapeDefault<'a>
impl<'a> Unpin for std::str::EscapeUnicode<'a>
impl<'a> Unpin for std::str::Lines<'a>
impl<'a> Unpin for LinesAny<'a>
impl<'a> Unpin for SplitAsciiWhitespace<'a>
impl<'a> Unpin for SplitWhitespace<'a>
impl<'a> Unpin for std::string::Drain<'a>
impl<'a> Unpin for Context<'a>
impl<'a, 'b> Unpin for DebugList<'a, 'b> where
'b: 'a,
impl<'a, 'b> Unpin for DebugMap<'a, 'b> where
'b: 'a,
impl<'a, 'b> Unpin for DebugSet<'a, 'b> where
'b: 'a,
impl<'a, 'b> Unpin for DebugStruct<'a, 'b> where
'b: 'a,
impl<'a, 'b> Unpin for DebugTuple<'a, 'b> where
'b: 'a,
impl<'a, 'b> Unpin for CharSliceSearcher<'a, 'b>
impl<'a, 'b> Unpin for StrSearcher<'a, 'b>
impl<'a, 'f> Unpin for VaList<'a, 'f> where
'f: 'a,
impl<'a, A> Unpin for std::option::Iter<'a, A>
impl<'a, A> Unpin for std::option::IterMut<'a, A>
impl<'a, F> Unpin for CharPredicateSearcher<'a, F> where
F: Unpin,
impl<'a, I, A> Unpin for Splice<'a, I, A> where
I: Unpin,
impl<'a, K> Unpin for std::collections::hash_set::Drain<'a, K> where
K: Unpin,
impl<'a, K> Unpin for std::collections::hash_set::Iter<'a, K>
impl<'a, K, F> Unpin for std::collections::hash_set::DrainFilter<'a, K, F> where
F: Unpin,
impl<'a, K, V> Unpin for std::collections::btree_map::Entry<'a, K, V> where
K: Unpin,
impl<'a, K, V> Unpin for std::collections::hash_map::Entry<'a, K, V> where
K: Unpin,
impl<'a, K, V> Unpin for std::collections::btree_map::Iter<'a, K, V>
impl<'a, K, V> Unpin for std::collections::btree_map::IterMut<'a, K, V>
impl<'a, K, V> Unpin for std::collections::btree_map::Keys<'a, K, V>
impl<'a, K, V> Unpin for std::collections::btree_map::OccupiedEntry<'a, K, V>
impl<'a, K, V> Unpin for std::collections::btree_map::OccupiedError<'a, K, V> where
V: Unpin,
impl<'a, K, V> Unpin for std::collections::btree_map::Range<'a, K, V>
impl<'a, K, V> Unpin for RangeMut<'a, K, V>
impl<'a, K, V> Unpin for std::collections::btree_map::VacantEntry<'a, K, V> where
K: Unpin,
impl<'a, K, V> Unpin for std::collections::btree_map::Values<'a, K, V>
impl<'a, K, V> Unpin for std::collections::btree_map::ValuesMut<'a, K, V>
impl<'a, K, V> Unpin for std::collections::hash_map::Iter<'a, K, V>
impl<'a, K, V> Unpin for std::collections::hash_map::IterMut<'a, K, V>
impl<'a, K, V> Unpin for std::collections::hash_map::Keys<'a, K, V>
impl<'a, K, V> Unpin for std::collections::hash_map::OccupiedEntry<'a, K, V> where
K: Unpin,
impl<'a, K, V> Unpin for std::collections::hash_map::OccupiedError<'a, K, V> where
K: Unpin,
V: Unpin,
impl<'a, K, V> Unpin for std::collections::hash_map::VacantEntry<'a, K, V> where
K: Unpin,
impl<'a, K, V> Unpin for std::collections::hash_map::Values<'a, K, V>
impl<'a, K, V> Unpin for std::collections::hash_map::ValuesMut<'a, K, V>
impl<'a, K, V, F> Unpin for std::collections::btree_map::DrainFilter<'a, K, V, F> where
F: Unpin,
impl<'a, K, V, F> Unpin for std::collections::hash_map::DrainFilter<'a, K, V, F> where
F: Unpin,
impl<'a, K, V, S> Unpin for RawEntryMut<'a, K, V, S>
impl<'a, K, V, S> Unpin for RawEntryBuilder<'a, K, V, S>
impl<'a, K, V, S> Unpin for RawEntryBuilderMut<'a, K, V, S>
impl<'a, K, V, S> Unpin for RawOccupiedEntryMut<'a, K, V, S>
impl<'a, K, V, S> Unpin for RawVacantEntryMut<'a, K, V, S>
impl<'a, T> Unpin for std::collections::binary_heap::Drain<'a, T>
impl<'a, T> Unpin for DrainSorted<'a, T>
impl<'a, T> Unpin for std::collections::binary_heap::Iter<'a, T>
impl<'a, T> Unpin for PeekMut<'a, T>
impl<'a, T> Unpin for std::collections::btree_set::Difference<'a, T>
impl<'a, T> Unpin for std::collections::btree_set::Intersection<'a, T>
impl<'a, T> Unpin for std::collections::btree_set::Iter<'a, T>
impl<'a, T> Unpin for std::collections::btree_set::Range<'a, T>
impl<'a, T> Unpin for std::collections::btree_set::SymmetricDifference<'a, T>
impl<'a, T> Unpin for std::collections::btree_set::Union<'a, T>
impl<'a, T> Unpin for std::collections::linked_list::Cursor<'a, T>
impl<'a, T> Unpin for CursorMut<'a, T>
impl<'a, T> Unpin for std::collections::linked_list::Iter<'a, T>
impl<'a, T> Unpin for std::collections::linked_list::IterMut<'a, T>
impl<'a, T> Unpin for std::collections::vec_deque::Iter<'a, T>
impl<'a, T> Unpin for std::collections::vec_deque::IterMut<'a, T>
impl<'a, T> Unpin for std::result::Iter<'a, T>
impl<'a, T> Unpin for std::result::IterMut<'a, T>
impl<'a, T> Unpin for Chunks<'a, T>
impl<'a, T> Unpin for ChunksExact<'a, T>
impl<'a, T> Unpin for ChunksExactMut<'a, T>
impl<'a, T> Unpin for ChunksMut<'a, T>
impl<'a, T> Unpin for std::slice::Iter<'a, T>
impl<'a, T> Unpin for std::slice::IterMut<'a, T>
impl<'a, T> Unpin for RChunks<'a, T>
impl<'a, T> Unpin for RChunksExact<'a, T>
impl<'a, T> Unpin for RChunksExactMut<'a, T>
impl<'a, T> Unpin for RChunksMut<'a, T>
impl<'a, T> Unpin for Windows<'a, T>
impl<'a, T> Unpin for std::sync::mpsc::Iter<'a, T>
impl<'a, T> Unpin for TryIter<'a, T>
impl<'a, T, A> Unpin for std::collections::vec_deque::Drain<'a, T, A>
impl<'a, T, A> Unpin for std::vec::Drain<'a, T, A>
impl<'a, T, F> Unpin for std::collections::btree_set::DrainFilter<'a, T, F> where
F: Unpin,
impl<'a, T, F> Unpin for std::collections::linked_list::DrainFilter<'a, T, F> where
F: Unpin,
impl<'a, T, F, A> Unpin for std::vec::DrainFilter<'a, T, F, A> where
F: Unpin,
impl<'a, T, P> Unpin for GroupBy<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for GroupByMut<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for std::slice::RSplit<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for RSplitMut<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for std::slice::RSplitN<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for RSplitNMut<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for std::slice::Split<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for SplitMut<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for std::slice::SplitN<'a, T, P> where
P: Unpin,
impl<'a, T, P> Unpin for SplitNMut<'a, T, P> where
P: Unpin,
impl<'a, T, S> Unpin for std::collections::hash_set::Difference<'a, T, S>
impl<'a, T, S> Unpin for std::collections::hash_set::Intersection<'a, T, S>
impl<'a, T, S> Unpin for std::collections::hash_set::SymmetricDifference<'a, T, S>
impl<'a, T, S> Unpin for std::collections::hash_set::Union<'a, T, S>
impl<'a, T, const N: usize> Unpin for ArrayChunks<'a, T, N>
impl<'a, T, const N: usize> Unpin for ArrayChunksMut<'a, T, N>
impl<'a, T, const N: usize> Unpin for ArrayWindows<'a, T, N>
impl<'a, T: ?Sized> Unpin for MutexGuard<'a, T>
impl<'a, T: ?Sized> Unpin for RwLockReadGuard<'a, T>
impl<'a, T: ?Sized> Unpin for RwLockWriteGuard<'a, T>
impl<'b, T: ?Sized> Unpin for Ref<'b, T>
impl<'b, T: ?Sized> Unpin for RefMut<'b, T>
impl<'f> Unpin for VaListImpl<'f>
impl<'fd> Unpin for BorrowedFd<'fd>
impl<'handle> Unpin for BorrowedHandle<'handle>
impl<'socket> Unpin for BorrowedSocket<'socket>
impl<A> Unpin for std::iter::Repeat<A> where
A: Unpin,
impl<A> Unpin for std::option::IntoIter<A> where
A: Unpin,
impl<B> Unpin for std::io::Lines<B> where
B: Unpin,
impl<B> Unpin for std::io::Split<B> where
B: Unpin,
impl<F> Unpin for FromFn<F> where
F: Unpin,
impl<F> Unpin for OnceWith<F> where
F: Unpin,
impl<F> Unpin for RepeatWith<F> where
F: Unpin,
impl<H> Unpin for BuildHasherDefault<H> where
H: Unpin,
impl<I> Unpin for DecodeUtf16<I> where
I: Unpin,
impl<I> Unpin for Cloned<I> where
I: Unpin,
impl<I> Unpin for Copied<I> where
I: Unpin,
impl<I> Unpin for Cycle<I> where
I: Unpin,
impl<I> Unpin for Enumerate<I> where
I: Unpin,
impl<I> Unpin for Flatten<I> where
I: Unpin,
<<I as Iterator>::Item as IntoIterator>::IntoIter: Unpin,
impl<I> Unpin for Fuse<I> where
I: Unpin,
impl<I> Unpin for Skip<I> where
I: Unpin,
impl<I> Unpin for StepBy<I> where
I: Unpin,
impl<I> Unpin for std::iter::Take<I> where
I: Unpin,
impl<I, U, F> Unpin for FlatMap<I, U, F> where
F: Unpin,
I: Unpin,
<U as IntoIterator>::IntoIter: Unpin,
impl<Idx> Unpin for std::ops::Range<Idx> where
Idx: Unpin,
impl<Idx> Unpin for RangeFrom<Idx> where
Idx: Unpin,
impl<Idx> Unpin for RangeInclusive<Idx> where
Idx: Unpin,
impl<Idx> Unpin for RangeTo<Idx> where
Idx: Unpin,
impl<Idx> Unpin for RangeToInclusive<Idx> where
Idx: Unpin,
impl<K> Unpin for std::collections::hash_set::IntoIter<K> where
K: Unpin,
impl<K, V> Unpin for std::collections::btree_map::IntoIter<K, V>
impl<K, V> Unpin for std::collections::btree_map::IntoKeys<K, V>
impl<K, V> Unpin for std::collections::btree_map::IntoValues<K, V>
impl<K, V> Unpin for BTreeMap<K, V>
impl<P> Unpin for Pin<P> where
P: Unpin,
impl<R> Unpin for BufReader<R> where
R: Unpin,
impl<R> Unpin for std::io::Bytes<R> where
R: Unpin,
impl<T> Unpin for Bound<T> where
T: Unpin,
impl<T> Unpin for Option<T> where
T: Unpin,
impl<T> Unpin for TryLockError<T> where
T: Unpin,
impl<T> Unpin for TrySendError<T> where
T: Unpin,
impl<T> Unpin for Poll<T> where
T: Unpin,
impl<T> Unpin for [T] where
T: Unpin,
impl<T> Unpin for Reverse<T> where
T: Unpin,
impl<T> Unpin for std::collections::binary_heap::IntoIter<T> where
T: Unpin,
impl<T> Unpin for IntoIterSorted<T> where
T: Unpin,
impl<T> Unpin for std::collections::btree_set::IntoIter<T>
impl<T> Unpin for std::collections::linked_list::IntoIter<T>
impl<T> Unpin for BTreeSet<T>
impl<T> Unpin for BinaryHeap<T> where
T: Unpin,
impl<T> Unpin for LinkedList<T>
impl<T> Unpin for std::io::Cursor<T> where
T: Unpin,
impl<T> Unpin for std::io::Take<T> where
T: Unpin,
impl<T> Unpin for std::iter::Empty<T> where
T: Unpin,
impl<T> Unpin for std::iter::Once<T> where
T: Unpin,
impl<T> Unpin for Rev<T> where
T: Unpin,
impl<T> Unpin for OnceCell<T> where
T: Unpin,
impl<T> Unpin for SyncOnceCell<T> where
T: Unpin,
impl<T> Unpin for Discriminant<T>
impl<T> Unpin for Saturating<T> where
T: Unpin,
impl<T> Unpin for Wrapping<T> where
T: Unpin,
impl<T> Unpin for AssertUnwindSafe<T> where
T: Unpin,
impl<T> Unpin for std::result::IntoIter<T> where
T: Unpin,
impl<T> Unpin for AtomicPtr<T>
impl<T> Unpin for std::sync::mpsc::IntoIter<T>
impl<T> Unpin for Receiver<T>
impl<T> Unpin for SendError<T> where
T: Unpin,
impl<T> Unpin for Sender<T>
impl<T> Unpin for SyncSender<T>
impl<T> Unpin for PoisonError<T> where
T: Unpin,
impl<T> Unpin for JoinHandle<T>
impl<T> Unpin for LocalKey<T>
impl<T> Unpin for MaybeUninit<T> where
T: Unpin,
impl<T, const N: usize> Unpin for [T; N] where
T: Unpin,
impl<T, const N: usize> Unpin for std::array::IntoIter<T, N> where
T: Unpin,
impl<T: ?Sized> Unpin for Cell<T> where
T: Unpin,
impl<T: ?Sized> Unpin for RefCell<T> where
T: Unpin,
impl<T: ?Sized> Unpin for UnsafeCell<T> where
T: Unpin,
impl<T: ?Sized> Unpin for ManuallyDrop<T> where
T: Unpin,
impl<T: ?Sized> Unpin for NonNull<T>
impl<T: ?Sized> Unpin for std::rc::Weak<T>
impl<T: ?Sized> Unpin for Mutex<T> where
T: Unpin,
impl<T: ?Sized> Unpin for RwLock<T> where
T: Unpin,
impl<T: ?Sized> Unpin for std::sync::Weak<T>
impl<T: ?Sized> Unpin for PhantomData<T> where
T: Unpin,
impl<W> Unpin for BufWriter<W> where
W: Unpin,
impl<W> Unpin for IntoInnerError<W> where
W: Unpin,
impl<W> Unpin for LineWriter<W> where
W: Unpin,
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/marker/trait.Unpin.html