Struct kvarn::prelude::Pin

1.33.0 · source ·
pub struct Pin<P> { /* private fields */ }
Expand description

A pinned pointer.

This is a wrapper around a kind of pointer which makes that pointer “pin” its value in place, preventing the value referenced by that pointer from being moved unless it implements Unpin.

See the pin module documentation for an explanation of pinning.

Implementations§

Construct a new Pin<P> around a pointer to some data of a type that implements Unpin.

Unlike Pin::new_unchecked, this method is safe because the pointer P dereferences to an Unpin type, which cancels the pinning guarantees.

Examples
use std::pin::Pin;

let mut val: u8 = 5;
// We can pin the value, since it doesn't care about being moved
let mut pinned: Pin<&mut u8> = Pin::new(&mut val);

Unwraps this Pin<P> returning the underlying pointer.

This requires that the data inside this Pin implements Unpin so that we can ignore the pinning invariants when unwrapping it.

Examples
use std::pin::Pin;

let mut val: u8 = 5;
let pinned: Pin<&mut u8> = Pin::new(&mut val);
// Unwrap the pin to get a reference to the value
let r = Pin::into_inner(pinned);
assert_eq!(*r, 5);

Construct a new Pin<P> around a reference to some data of a type that may or may not implement Unpin.

If pointer dereferences to an Unpin type, Pin::new should be used instead.

Safety

This constructor is unsafe because we cannot guarantee that the data pointed to by pointer is pinned, meaning that the data will not be moved or its storage invalidated until it gets dropped. If the constructed Pin<P> does not guarantee that the data P points to is pinned, that is a violation of the API contract and may lead to undefined behavior in later (safe) operations.

By using this method, you are making a promise about the P::Deref and P::DerefMut implementations, if they exist. Most importantly, they must not move out of their self arguments: Pin::as_mut and Pin::as_ref will call DerefMut::deref_mut and Deref::deref on the pinned pointer and expect these methods to uphold the pinning invariants. Moreover, by calling this method you promise that the reference P dereferences to will not be moved out of again; in particular, it must not be possible to obtain a &mut P::Target and then move out of that reference (using, for example mem::swap).

For example, calling Pin::new_unchecked on an &'a mut T is unsafe because while you are able to pin it for the given lifetime 'a, you have no control over whether it is kept pinned once 'a ends:

use std::mem;
use std::pin::Pin;

fn move_pinned_ref<T>(mut a: T, mut b: T) {
    unsafe {
        let p: Pin<&mut T> = Pin::new_unchecked(&mut a);
        // This should mean the pointee `a` can never move again.
    }
    mem::swap(&mut a, &mut b); // Potential UB down the road ⚠️
    // The address of `a` changed to `b`'s stack slot, so `a` got moved even
    // though we have previously pinned it! We have violated the pinning API contract.
}

A value, once pinned, must remain pinned forever (unless its type implements Unpin).

Similarly, calling Pin::new_unchecked on an Rc<T> is unsafe because there could be aliases to the same data that are not subject to the pinning restrictions:

use std::rc::Rc;
use std::pin::Pin;

fn move_pinned_rc<T>(mut x: Rc<T>) {
    let pinned = unsafe { Pin::new_unchecked(Rc::clone(&x)) };
    {
        let p: Pin<&T> = pinned.as_ref();
        // This should mean the pointee can never move again.
    }
    drop(pinned);
    let content = Rc::get_mut(&mut x).unwrap(); // Potential UB down the road ⚠️
    // Now, if `x` was the only reference, we have a mutable reference to
    // data that we pinned above, which we could use to move it as we have
    // seen in the previous example. We have violated the pinning API contract.
 }
Pinning of closure captures

Particular care is required when using Pin::new_unchecked in a closure: Pin::new_unchecked(&mut var) where var is a by-value (moved) closure capture implicitly makes the promise that the closure itself is pinned, and that all uses of this closure capture respect that pinning.

use std::pin::Pin;
use std::task::Context;
use std::future::Future;

fn move_pinned_closure(mut x: impl Future, cx: &mut Context<'_>) {
    // Create a closure that moves `x`, and then internally uses it in a pinned way.
    let mut closure = move || unsafe {
        let _ignore = Pin::new_unchecked(&mut x).poll(cx);
    };
    // Call the closure, so the future can assume it has been pinned.
    closure();
    // Move the closure somewhere else. This also moves `x`!
    let mut moved = closure;
    // Calling it again means we polled the future from two different locations,
    // violating the pinning API contract.
    moved(); // Potential UB ⚠️
}

When passing a closure to another API, it might be moving the closure any time, so Pin::new_unchecked on closure captures may only be used if the API explicitly documents that the closure is pinned.

The better alternative is to avoid all that trouble and do the pinning in the outer function instead (here using the pin! macro):

use std::pin::pin;
use std::task::Context;
use std::future::Future;

fn move_pinned_closure(mut x: impl Future, cx: &mut Context<'_>) {
    let mut x = pin!(x);
    // Create a closure that captures `x: Pin<&mut _>`, which is safe to move.
    let mut closure = move || {
        let _ignore = x.as_mut().poll(cx);
    };
    // Call the closure, so the future can assume it has been pinned.
    closure();
    // Move the closure somewhere else.
    let mut moved = closure;
    // Calling it again here is fine (except that we might be polling a future that already
    // returned `Poll::Ready`, but that is a separate problem).
    moved();
}

Gets a pinned shared reference from this pinned pointer.

This is a generic method to go from &Pin<Pointer<T>> to Pin<&T>. It is safe because, as part of the contract of Pin::new_unchecked, the pointee cannot move after Pin<Pointer<T>> got created. “Malicious” implementations of Pointer::Deref are likewise ruled out by the contract of Pin::new_unchecked.

Unwraps this Pin<P> returning the underlying pointer.

Safety

This function is unsafe. You must guarantee that you will continue to treat the pointer P as pinned after you call this function, so that the invariants on the Pin type can be upheld. If the code using the resulting P does not continue to maintain the pinning invariants that is a violation of the API contract and may lead to undefined behavior in later (safe) operations.

If the underlying data is Unpin, Pin::into_inner should be used instead.

Gets a pinned mutable reference from this pinned pointer.

This is a generic method to go from &mut Pin<Pointer<T>> to Pin<&mut T>. It is safe because, as part of the contract of Pin::new_unchecked, the pointee cannot move after Pin<Pointer<T>> got created. “Malicious” implementations of Pointer::DerefMut are likewise ruled out by the contract of Pin::new_unchecked.

This method is useful when doing multiple calls to functions that consume the pinned type.

Example
use std::pin::Pin;

impl Type {
    fn method(self: Pin<&mut Self>) {
        // do something
    }

    fn call_method_twice(mut self: Pin<&mut Self>) {
        // `method` consumes `self`, so reborrow the `Pin<&mut Self>` via `as_mut`.
        self.as_mut().method();
        self.as_mut().method();
    }
}

Assigns a new value to the memory behind the pinned reference.

This overwrites pinned data, but that is okay: its destructor gets run before being overwritten, so no pinning guarantee is violated.

Example
use std::pin::Pin;

let mut val: u8 = 5;
let mut pinned: Pin<&mut u8> = Pin::new(&mut val);
println!("{}", pinned); // 5
pinned.as_mut().set(10);
println!("{}", pinned); // 10

Constructs a new pin by mapping the interior value.

For example, if you wanted to get a Pin of a field of something, you could use this to get access to that field in one line of code. However, there are several gotchas with these “pinning projections”; see the pin module documentation for further details on that topic.

Safety

This function is unsafe. You must guarantee that the data you return will not move so long as the argument value does not move (for example, because it is one of the fields of that value), and also that you do not move out of the argument you receive to the interior function.

Gets a shared reference out of a pin.

This is safe because it is not possible to move out of a shared reference. It may seem like there is an issue here with interior mutability: in fact, it is possible to move a T out of a &RefCell<T>. However, this is not a problem as long as there does not also exist a Pin<&T> pointing to the same data, and RefCell<T> does not let you create a pinned reference to its contents. See the discussion on “pinning projections” for further details.

Note: Pin also implements Deref to the target, which can be used to access the inner value. However, Deref only provides a reference that lives for as long as the borrow of the Pin, not the lifetime of the Pin itself. This method allows turning the Pin into a reference with the same lifetime as the original Pin.

Converts this Pin<&mut T> into a Pin<&T> with the same lifetime.

Gets a mutable reference to the data inside of this Pin.

This requires that the data inside this Pin is Unpin.

Note: Pin also implements DerefMut to the data, which can be used to access the inner value. However, DerefMut only provides a reference that lives for as long as the borrow of the Pin, not the lifetime of the Pin itself. This method allows turning the Pin into a reference with the same lifetime as the original Pin.

Gets a mutable reference to the data inside of this Pin.

Safety

This function is unsafe. You must guarantee that you will never move the data out of the mutable reference you receive when you call this function, so that the invariants on the Pin type can be upheld.

If the underlying data is Unpin, Pin::get_mut should be used instead.

Construct a new pin by mapping the interior value.

For example, if you wanted to get a Pin of a field of something, you could use this to get access to that field in one line of code. However, there are several gotchas with these “pinning projections”; see the pin module documentation for further details on that topic.

Safety

This function is unsafe. You must guarantee that the data you return will not move so long as the argument value does not move (for example, because it is one of the fields of that value), and also that you do not move out of the argument you receive to the interior function.

Get a pinned reference from a static reference.

This is safe, because T is borrowed for the 'static lifetime, which never ends.

🔬This is a nightly-only experimental API. (pin_deref_mut)

Gets a pinned mutable reference from this nested pinned pointer.

This is a generic method to go from Pin<&mut Pin<Pointer<T>>> to Pin<&mut T>. It is safe because the existence of a Pin<Pointer<T>> ensures that the pointee, T, cannot move in the future, and this method does not enable the pointee to move. “Malicious” implementations of P::DerefMut are likewise ruled out by the contract of Pin::new_unchecked.

Get a pinned mutable reference from a static mutable reference.

This is safe, because T is borrowed for the 'static lifetime, which never ends.

Trait Implementations§

Attempts to return the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more
Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to poll_read. Read more
🔬This is a nightly-only experimental API. (async_iterator)
The type of items yielded by the async iterator.
🔬This is a nightly-only experimental API. (async_iterator)
Attempt to pull out the next value of this async iterator, registering the current task for wakeup if the value is not yet available, and returning None if the async iterator is exhausted. Read more
🔬This is a nightly-only experimental API. (async_iterator)
Returns the bounds on the remaining length of the async iterator. Read more
Attempts to read from the AsyncRead into buf. Read more
Attempts to seek to an offset, in bytes, in a stream. Read more
Waits for a seek operation to complete. Read more
Attempt to write bytes from buf into the object. Read more
Like poll_write, except that it writes from a slice of buffers. Read more
Determines if this writer has an efficient poll_write_vectored implementation. Read more
Attempts to flush the object, ensuring that any buffered data reach their destination. Read more
Initiates or attempts to shut down this writer, returning success when the I/O connection has completely shut down. Read more
Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
The resulting type after dereferencing.
Dereferences the value.
Mutably dereferences the value.
Formats the value using the given formatter. Read more

Converts a Box<T> into a Pin<Box<T>>. If T does not implement Unpin, then *boxed will be pinned in memory and unable to be moved.

This conversion does not allocate on the heap and happens in place.

This is also available via Box::into_pin.

Constructing and pinning a Box with <Pin<Box<T>>>::from(Box::new(x)) can also be written more concisely using Box::pin(x). This From implementation is useful if you already have a Box<T>, or you are constructing a (pinned) Box in a different way than with Box::new.

Returns true if the underlying future should no longer be polled.
Returns true if the stream should no longer be polled.
The type of value produced on completion.
Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more
🔬This is a nightly-only experimental API. (generator_trait)
The type of value this generator yields. Read more
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The type of value this generator returns. Read more
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Resumes the execution of this generator. Read more
🔬This is a nightly-only experimental API. (generator_trait)
The type of value this generator yields. Read more
🔬This is a nightly-only experimental API. (generator_trait)
The type of value this generator returns. Read more
🔬This is a nightly-only experimental API. (generator_trait)
Resumes the execution of this generator. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==.
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
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This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
Formats the value using the given formatter.
The type of value produced by the sink when an error occurs.
Attempts to prepare the Sink to receive a value. Read more
Begin the process of sending a value to the sink. Each call to this function must be preceded by a successful call to poll_ready which returned Poll::Ready(Ok(())). Read more
Flush any remaining output from this sink. Read more
Flush any remaining output and close this sink, if necessary. Read more
Values yielded by the stream.
Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted. Read more
Returns the bounds on the remaining length of the stream. Read more
Convert an owned instance into a (conceptually owned) fat pointer. Read more
Drops the future represented by the given fat pointer. Read more
Convert an owned instance into a (conceptually owned) fat pointer. Read more
Drops the future represented by the given fat pointer. Read more
Convert an owned instance into a (conceptually owned) fat pointer. Read more
Drops the future represented by the given fat pointer. Read more
Convert an owned instance into a (conceptually owned) fat pointer. Read more
Drops the future represented by the given fat pointer. Read more
Convert an owned instance into a (conceptually owned) fat pointer. Read more
Drops the future represented by the given fat pointer. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
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Reads all bytes until a newline (the 0xA byte) is reached, and append them to the provided buffer. Read more
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Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more
Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read. Read more
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Pulls some bytes from this source into the specified buffer, advancing the buffer’s internal cursor. Read more
Reads the exact number of bytes required to fill buf. Read more
Reads an unsigned 8 bit integer from the underlying reader. Read more
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Reads a signed 32-bit integer in big-endian order from the underlying reader. Read more
Reads an unsigned 64-bit integer in big-endian order from the underlying reader. Read more
Reads an signed 64-bit integer in big-endian order from the underlying reader. Read more
Reads an unsigned 128-bit integer in big-endian order from the underlying reader. Read more
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Reads an 32-bit floating point type in big-endian order from the underlying reader. Read more
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Reads an unsigned 16-bit integer in little-endian order from the underlying reader. Read more
Reads a signed 16-bit integer in little-endian order from the underlying reader. Read more
Reads an unsigned 32-bit integer in little-endian order from the underlying reader. Read more
Reads a signed 32-bit integer in little-endian order from the underlying reader. Read more
Reads an unsigned 64-bit integer in little-endian order from the underlying reader. Read more
Reads an signed 64-bit integer in little-endian order from the underlying reader. Read more
Reads an unsigned 128-bit integer in little-endian order from the underlying reader. Read more
Reads an signed 128-bit integer in little-endian order from the underlying reader. Read more
Reads an 32-bit floating point type in little-endian order from the underlying reader. Read more
Reads an 64-bit floating point type in little-endian order from the underlying reader. Read more
Reads all bytes until EOF in this source, placing them into buf. Read more
Reads all bytes until EOF in this source, appending them to buf. Read more
Creates an adaptor which reads at most limit bytes from it. Read more
Creates a future which will seek an IO object, and then yield the new position in the object and the object itself. Read more
Creates a future which will rewind to the beginning of the stream. Read more
Creates a future which will return the current seek position from the start of the stream. Read more
Writes a buffer into this writer, returning how many bytes were written. Read more
Like write, except that it writes from a slice of buffers. Read more
Writes a buffer into this writer, advancing the buffer’s internal cursor. Read more
Attempts to write an entire buffer into this writer. Read more
Attempts to write an entire buffer into this writer. Read more
Writes an unsigned 8-bit integer to the underlying writer. Read more
Writes a signed 8-bit integer to the underlying writer. Read more
Writes an unsigned 16-bit integer in big-endian order to the underlying writer. Read more
Writes a signed 16-bit integer in big-endian order to the underlying writer. Read more
Writes an unsigned 32-bit integer in big-endian order to the underlying writer. Read more
Writes a signed 32-bit integer in big-endian order to the underlying writer. Read more
Writes an unsigned 64-bit integer in big-endian order to the underlying writer. Read more
Writes an signed 64-bit integer in big-endian order to the underlying writer. Read more
Writes an unsigned 128-bit integer in big-endian order to the underlying writer. Read more
Writes an signed 128-bit integer in big-endian order to the underlying writer. Read more
Writes an 32-bit floating point type in big-endian order to the underlying writer. Read more
Writes an 64-bit floating point type in big-endian order to the underlying writer. Read more
Writes an unsigned 16-bit integer in little-endian order to the underlying writer. Read more
Writes a signed 16-bit integer in little-endian order to the underlying writer. Read more
Writes an unsigned 32-bit integer in little-endian order to the underlying writer. Read more
Writes a signed 32-bit integer in little-endian order to the underlying writer. Read more
Writes an unsigned 64-bit integer in little-endian order to the underlying writer. Read more
Writes an signed 64-bit integer in little-endian order to the underlying writer. Read more
Writes an unsigned 128-bit integer in little-endian order to the underlying writer. Read more
Writes an signed 128-bit integer in little-endian order to the underlying writer. Read more
Writes an 32-bit floating point type in little-endian order to the underlying writer. Read more
Writes an 64-bit floating point type in little-endian order to the underlying writer. Read more
Flushes this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
Shuts down the output stream, ensuring that the value can be dropped cleanly. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
Compare self to key and return true if they are equal.

Returns the argument unchanged.

Map this future’s output to a different type, returning a new future of the resulting type. Read more
Map this future’s output to a different type, returning a new future of the resulting type. Read more
Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more
Wrap this future in an Either future, making it the left-hand variant of that Either. Read more
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Convert this future into a single element stream. Read more
Flatten the execution of this future when the output of this future is itself another future. Read more
Flatten the execution of this future when the successful result of this future is a stream. Read more
Fuse a future such that poll will never again be called once it has completed. This method can be used to turn any Future into a FusedFuture. Read more
Do something with the output of a future before passing it on. Read more
Available on crate feature std only.
Catches unwinding panics while polling the future. Read more
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Create a cloneable handle to this future where all handles will resolve to the same result. Read more
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Wrap the future in a Box, pinning it. Read more
Available on crate feature alloc only.
Wrap the future in a Box, pinning it. Read more
A convenience for calling Future::poll on Unpin future types.
Evaluates and consumes the future, returning the resulting output if the future is ready after the first call to Future::poll. Read more
Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The output that the future will produce on completion.
Which kind of future are we turning this into?
Creates a future from a value. Read more
Should always be Self
Composes a function in front of the sink. Read more
Composes a function in front of the sink. Read more
Transforms the error returned by the sink.
Map this sink’s error to a different error type using the Into trait. Read more
Available on crate feature alloc only.
Adds a fixed-size buffer to the current sink. Read more
Close the sink.
Fanout items to multiple sinks. Read more
Flush the sink, processing all pending items. Read more
A future that completes after the given item has been fully processed into the sink, including flushing. Read more
A future that completes after the given item has been received by the sink. Read more
A future that completes after the given stream has been fully processed into the sink, including flushing. Read more
Wrap this sink in an Either sink, making it the left-hand variant of that Either. Read more
Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more
A convenience method for calling Sink::poll_ready on Unpin sink types.
A convenience method for calling Sink::start_send on Unpin sink types.
A convenience method for calling Sink::poll_flush on Unpin sink types.
A convenience method for calling Sink::poll_close on Unpin sink types.
Creates a future that resolves to the next item in the stream. Read more
Converts this stream into a future of (next_item, tail_of_stream). If the stream terminates, then the next item is None. Read more
Maps this stream’s items to a different type, returning a new stream of the resulting type. Read more
Creates a stream which gives the current iteration count as well as the next value. Read more
Filters the values produced by this stream according to the provided asynchronous predicate. Read more
Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
Computes from this stream’s items new items of a different type using an asynchronous closure. Read more
Transforms a stream into a collection, returning a future representing the result of that computation. Read more
Converts a stream of pairs into a future, which resolves to pair of containers. Read more
Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
Drives the stream to completion, counting the number of items. Read more
Repeats a stream endlessly. Read more
Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
Execute predicate over asynchronous stream, and return true if any element in stream satisfied a predicate. Read more
Execute predicate over asynchronous stream, and return true if all element in stream satisfied a predicate. Read more
Flattens a stream of streams into just one continuous stream. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
Flattens a stream of streams into just one continuous stream. Polls inner streams concurrently. Read more
Maps a stream like StreamExt::map but flattens nested Streams. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
Maps a stream like StreamExt::map but flattens nested Streams and polls them concurrently, yielding items in any order, as they made available. Read more
Combinator similar to StreamExt::fold that holds internal state and produces a new stream. Read more
Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
Take elements from this stream while the provided asynchronous predicate resolves to true. Read more
Take elements from this stream until the provided future resolves. Read more
Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more
Creates a new stream of at most n items of the underlying stream. Read more
Creates a new stream which skips n items of the underlying stream. Read more
Fuse a stream such that poll_next will never again be called once it has finished. This method can be used to turn any Stream into a FusedStream. Read more
Borrows a stream, rather than consuming it. Read more
Available on crate feature std only.
Catches unwinding panics while polling the stream. Read more
Available on crate feature alloc only.
Wrap the stream in a Box, pinning it. Read more
Available on crate feature alloc only.
Wrap the stream in a Box, pinning it. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
An adaptor for creating a buffered list of pending futures. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
An adaptor for creating a buffered list of pending futures (unordered). Read more
An adapter for zipping two streams together. Read more
Adapter for chaining two streams. Read more
Creates a new stream which exposes a peek method. Read more
Available on crate feature alloc only.
An adaptor for chunking up items of the stream inside a vector. Read more
Available on crate feature alloc only.
An adaptor for chunking up ready items of the stream inside a vector. Read more
Available on crate feature sink only.
A future that completes after the given stream has been fully processed into the sink and the sink has been flushed and closed. Read more
Available on crate feature sink and non-futures_no_atomic_cas and crate feature alloc only.
Splits this Stream + Sink object into separate Sink and Stream objects. Read more
Do something with each item of this stream, afterwards passing it on. Read more
Wrap this stream in an Either stream, making it the left-hand variant of that Either. Read more
Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more
A convenience method for calling Stream::poll_next on Unpin stream types.
Returns a Future that resolves when the next item in this stream is ready. Read more
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
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The type returned in the event of a conversion error.
Performs the conversion.
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Poll this TryFuture as if it were a Future. Read more
Available on crate feature sink only.
Flattens the execution of this future when the successful result of this future is a Sink. Read more
Maps this future’s success value to a different value. Read more
Maps this future’s success value to a different value, and permits for error handling resulting in the same type. Read more
Maps this future’s error value to a different value. Read more
Maps this future’s Error to a new error type using the Into trait. Read more
Maps this future’s Ok to a new type using the Into trait.
Executes another future after this one resolves successfully. The success value is passed to a closure to create this subsequent future. Read more
Executes another future if this one resolves to an error. The error value is passed to a closure to create this subsequent future. Read more
Do something with the success value of a future before passing it on. Read more
Do something with the error value of a future before passing it on. Read more
Flatten the execution of this future when the successful result of this future is another future. Read more
Flatten the execution of this future when the successful result of this future is a stream. Read more
Unwraps this future’s output, producing a future with this future’s Ok type as its Output type. Read more
Wraps a [TryFuture] into a type that implements Future. Read more
A convenience method for calling [TryFuture::try_poll] on Unpin future types.
The type returned in the event of a conversion error.
Performs the conversion.
The type of successful values yielded by this future
The type of failures yielded by this future
Poll this TryStream as if it were a Stream. Read more
Wraps the current stream in a new stream which converts the error type into the one provided. Read more
Wraps the current stream in a new stream which maps the success value using the provided closure. Read more
Wraps the current stream in a new stream which maps the error value using the provided closure. Read more
Chain on a computation for when a value is ready, passing the successful results to the provided closure f. Read more
Chain on a computation for when an error happens, passing the erroneous result to the provided closure f. Read more
Do something with the success value of this stream, afterwards passing it on. Read more
Do something with the error value of this stream, afterwards passing it on. Read more
Wraps a [TryStream] into a type that implements Stream Read more
Creates a future that attempts to resolve the next item in the stream. If an error is encountered before the next item, the error is returned instead. Read more
Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
Take elements on this stream while the provided asynchronous predicate resolves to true. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
Attempts to run this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available, exiting as soon as an error occurs. Read more
Attempt to transform a stream into a collection, returning a future representing the result of that computation. Read more
Available on crate feature alloc only.
An adaptor for chunking up successful items of the stream inside a vector. Read more
Attempt to filter the values produced by this stream according to the provided asynchronous closure. Read more
Attempt to filter the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
Flattens a stream of streams into just one continuous stream. Read more
Attempt to execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
Attempt to concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
Attempt to execute several futures from a stream concurrently (unordered). Read more
Available on non-futures_no_atomic_cas and crate feature alloc only.
Attempt to execute several futures from a stream concurrently. Read more
A convenience method for calling [TryStream::try_poll_next] on Unpin stream types.
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more