[−][src]Trait pin_project::UnsafeUnpin

[+] Show declaration

pub unsafe trait UnsafeUnpin { }

[−]

A trait used for custom implementations of Unpin. This trait is used in conjunction with the UnsafeUnpin argument to #[pin_project]

The Rust Unpin trait is safe to implement - by itself, implementing it cannot lead to undefined behavior. Undefined behavior can only occur when other unsafe code is used.

It turns out that using pin projections, which requires unsafe code, imposes additional requirements on an Unpin impl. Normally, all of this unsafety is contained within this crate, ensuring that it's impossible for you to violate any of the guarantees required by pin projection.

However, things change if you want to provide a custom Unpin impl for your #[pin_project] type. As stated in the Rust documentation, you must be sure to only implement Unpin when all of your #[pin] fields (i.e. structurally pinned fields) are also Unpin.

To help highlight this unsafety, the UnsafeUnpin trait is provided. Implementing this trait is logically equivalent to implementing Unpin - this crate will generate an Unpin impl for your type that 'forwards' to your UnsafeUnpin impl. However, this trait is unsafe - since your type uses structural pinning (otherwise, you wouldn't be using this crate!), you must be sure that your UnsafeUnpin impls follows all of the requirements for an Unpin impl of a structurally-pinned type.

Note that if you specify #[pin_project(UnsafeUnpin)], but do not provide an impl of UnsafeUnpin, your type will never implement Unpin. This is effectively the same thing as adding a PhantomPinned to your type.

Since this trait is unsafe, impls of it will be detected by the unsafe_code lint, and by tools like cargo geiger.

Examples

An UnsafeUnpin impl which, in addition to requiring that structurally pinned fields be Unpin, imposes an additional requirement:

use pin_project::{pin_project, UnsafeUnpin};

#[pin_project(UnsafeUnpin)]
struct Foo<K, V> {
    #[pin]
    field_1: K,
    field_2: V,
}

unsafe impl<K, V> UnsafeUnpin for Foo<K, V> where K: Unpin + Clone {}

Implementors

`impl<Fut> UnsafeUnpin for Fuse<Fut>`

`impl<F> UnsafeUnpin for Flatten<F> where F: Future,`

`impl<F> UnsafeUnpin for FlattenStream<F> where F: Future,`

`impl<Fut, F> UnsafeUnpin for Map<Fut, F>`

`impl<F> UnsafeUnpin for IntoStream<F>`

`impl<Fut, T> UnsafeUnpin for MapInto<Fut, T>`

`impl<Fut1, Fut2, F> UnsafeUnpin for Then<Fut1, Fut2, F>`

`impl<Fut, F> UnsafeUnpin for Inspect<Fut, F>`

`impl<Fut> UnsafeUnpin for NeverError<Fut>`

`impl<Fut> UnsafeUnpin for UnitError<Fut>`

`impl<Fut> UnsafeUnpin for CatchUnwind<Fut>`

`impl<Fut: Future> UnsafeUnpin for Remote<Fut>`

`impl<Fut> UnsafeUnpin for IntoFuture<Fut>`

`impl<Fut1, Fut2> UnsafeUnpin for TryFlatten<Fut1, Fut2>`

`impl<Fut> UnsafeUnpin for TryFlattenStream<Fut> where Fut: TryFuture,`

`impl<Fut, Si> UnsafeUnpin for FlattenSink<Fut, Si>`

`impl<Fut1, Fut2, F> UnsafeUnpin for AndThen<Fut1, Fut2, F>`

`impl<Fut1, Fut2, F> UnsafeUnpin for OrElse<Fut1, Fut2, F>`

`impl<Fut, E> UnsafeUnpin for ErrInto<Fut, E>`

`impl<Fut, E> UnsafeUnpin for OkInto<Fut, E>`

`impl<Fut, F> UnsafeUnpin for InspectOk<Fut, F>`

`impl<Fut, F> UnsafeUnpin for InspectErr<Fut, F>`

`impl<Fut, F> UnsafeUnpin for MapOk<Fut, F>`

`impl<Fut, F> UnsafeUnpin for MapErr<Fut, F>`

`impl<Fut, F, G> UnsafeUnpin for MapOkOrElse<Fut, F, G>`

`impl<Fut, F> UnsafeUnpin for UnwrapOrElse<Fut, F>`

`impl<Fut: Future> UnsafeUnpin for MaybeDone<Fut>`

`impl<Fut: TryFuture> UnsafeUnpin for TryMaybeDone<Fut>`

`impl<F> UnsafeUnpin for OptionFuture<F>`

`impl<Fut1: Future, Fut2: Future> UnsafeUnpin for Join<Fut1, Fut2>`

`impl<Fut1: Future, Fut2: Future, Fut3: Future> UnsafeUnpin for Join3<Fut1, Fut2, Fut3>`

`impl<Fut1: Future, Fut2: Future, Fut3: Future, Fut4: Future> UnsafeUnpin for Join4<Fut1, Fut2, Fut3, Fut4>`

`impl<Fut1: Future, Fut2: Future, Fut3: Future, Fut4: Future, Fut5: Future> UnsafeUnpin for Join5<Fut1, Fut2, Fut3, Fut4, Fut5>`

`impl<Fut1: TryFuture, Fut2: TryFuture> UnsafeUnpin for TryJoin<Fut1, Fut2>`

`impl<Fut1: TryFuture, Fut2: TryFuture, Fut3: TryFuture> UnsafeUnpin for TryJoin3<Fut1, Fut2, Fut3>`

`impl<Fut1: TryFuture, Fut2: TryFuture, Fut3: TryFuture, Fut4: TryFuture> UnsafeUnpin for TryJoin4<Fut1, Fut2, Fut3, Fut4>`

`impl<Fut1: TryFuture, Fut2: TryFuture, Fut3: TryFuture, Fut4: TryFuture, Fut5: TryFuture> UnsafeUnpin for TryJoin5<Fut1, Fut2, Fut3, Fut4, Fut5>`

`impl<A, B> UnsafeUnpin for Either<A, B>`

`impl<Fut> UnsafeUnpin for Abortable<Fut>`

`impl<St1, St2> UnsafeUnpin for Chain<St1, St2>`

`impl<St, C> UnsafeUnpin for Collect<St, C>`

`impl<St: Stream> UnsafeUnpin for Concat<St>`

`impl<St> UnsafeUnpin for Enumerate<St>`

`impl<St, Fut, F> UnsafeUnpin for Filter<St, Fut, F> where St: Stream,`

`impl<St, Fut, F> UnsafeUnpin for FilterMap<St, Fut, F>`

`impl<St> UnsafeUnpin for Flatten<St> where St: Stream,`

`impl<St, Fut, T, F> UnsafeUnpin for Fold<St, Fut, T, F>`

`impl<St, Si> UnsafeUnpin for Forward<St, Si> where St: TryStream,`

`impl<St, Fut, F> UnsafeUnpin for ForEach<St, Fut, F>`

`impl<St> UnsafeUnpin for Fuse<St>`

`impl<St, F> UnsafeUnpin for Inspect<St, F>`

`impl<St, F> UnsafeUnpin for Map<St, F>`

`impl<St, U, F> UnsafeUnpin for FlatMap<St, U, F>`

`impl<St: Stream> UnsafeUnpin for Peekable<St>`

`impl<'a, St: Stream> UnsafeUnpin for Peek<'a, St>`

`impl<St> UnsafeUnpin for Skip<St>`

`impl<St, Fut, F> UnsafeUnpin for SkipWhile<St, Fut, F> where St: Stream,`

`impl<St> UnsafeUnpin for Take<St>`

`impl<St: Stream, Fut, F> UnsafeUnpin for TakeWhile<St, Fut, F>`

`impl<St: Stream, Fut: Future> UnsafeUnpin for TakeUntil<St, Fut>`

`impl<St, Fut, F> UnsafeUnpin for Then<St, Fut, F>`

`impl<St1: Stream, St2: Stream> UnsafeUnpin for Zip<St1, St2>`

`impl<St: Stream> UnsafeUnpin for Chunks<St>`

`impl<St: Stream> UnsafeUnpin for ReadyChunks<St>`

`impl<St: Stream, S, Fut, F> UnsafeUnpin for Scan<St, S, Fut, F>`

`impl<St> UnsafeUnpin for BufferUnordered<St> where St: Stream,`

`impl<St> UnsafeUnpin for Buffered<St> where St: Stream, St::Item: Future,`

`impl<St, Fut, F> UnsafeUnpin for ForEachConcurrent<St, Fut, F>`

`impl<St> UnsafeUnpin for CatchUnwind<St>`

`impl<St, Fut, F> UnsafeUnpin for AndThen<St, Fut, F>`

`impl<St, E> UnsafeUnpin for ErrInto<St, E>`

`impl<St, F> UnsafeUnpin for InspectOk<St, F>`

`impl<St, F> UnsafeUnpin for InspectErr<St, F>`

`impl<St> UnsafeUnpin for IntoStream<St>`

`impl<St, F> UnsafeUnpin for MapOk<St, F>`

`impl<St, F> UnsafeUnpin for MapErr<St, F>`

`impl<St, Fut, F> UnsafeUnpin for OrElse<St, Fut, F>`

`impl<St, Fut, F> UnsafeUnpin for TryForEach<St, Fut, F>`

`impl<St, Fut, F> UnsafeUnpin for TryFilter<St, Fut, F> where St: TryStream,`

`impl<St, Fut, F> UnsafeUnpin for TryFilterMap<St, Fut, F>`

`impl<St> UnsafeUnpin for TryFlatten<St> where St: TryStream,`

`impl<St, C> UnsafeUnpin for TryCollect<St, C>`

`impl<St: TryStream> UnsafeUnpin for TryConcat<St>`

`impl<St, Fut, T, F> UnsafeUnpin for TryFold<St, Fut, T, F>`

`impl<T, F, Fut> UnsafeUnpin for TryUnfold<T, F, Fut>`

`impl<St, Fut, F> UnsafeUnpin for TrySkipWhile<St, Fut, F> where St: TryStream,`

`impl<St, Fut, F> UnsafeUnpin for TryTakeWhile<St, Fut, F> where St: TryStream,`

`impl<St> UnsafeUnpin for TryBufferUnordered<St> where St: TryStream,`

`impl<St, Fut, F> UnsafeUnpin for TryForEachConcurrent<St, Fut, F>`

`impl<Fut> UnsafeUnpin for Once<Fut>`

`impl<St1, St2> UnsafeUnpin for Select<St1, St2>`

`impl<T, F, Fut> UnsafeUnpin for Unfold<T, F, Fut>`

`impl<Si1, Si2> UnsafeUnpin for Fanout<Si1, Si2>`

`impl<Si: Sink<Item>, Item, E> UnsafeUnpin for SinkErrInto<Si, Item, E>`

`impl<Si, F> UnsafeUnpin for SinkMapErr<Si, F>`

`impl<Si, Item, U, Fut, F> UnsafeUnpin for With<Si, Item, U, Fut, F>`

`impl<Si, Item, U, St, F> UnsafeUnpin for WithFlatMap<Si, Item, U, St, F>`

`impl<Si, Item> UnsafeUnpin for Buffer<Si, Item>`

`impl<R> UnsafeUnpin for BufReader<R>`

`impl<W> UnsafeUnpin for BufWriter<W>`

`impl<T, U> UnsafeUnpin for Chain<T, U>`

`impl<'a, R, W: ?Sized> UnsafeUnpin for Copy<'a, R, W>`

`impl<'a, R, W: ?Sized> UnsafeUnpin for CopyBuf<'a, R, W>`

`impl<W, Item> UnsafeUnpin for IntoSink<W, Item>`

`impl<R> UnsafeUnpin for Lines<R>`

`impl<R> UnsafeUnpin for Take<R>`