Trait AsyncWriteExt

pub trait AsyncWriteExt: AsyncWrite {
    // Provided methods
    fn flush(&mut self) -> Flush<'_, Self> 
       where Self: Unpin { ... }
    fn close(&mut self) -> Close<'_, Self> 
       where Self: Unpin { ... }
    fn write<'a>(&'a mut self, buf: &'a [u8]) -> Write<'a, Self> 
       where Self: Unpin { ... }
    fn write_vectored<'a>(
        &'a mut self,
        bufs: &'a [IoSlice<'a>],
    ) -> WriteVectored<'a, Self> 
       where Self: Unpin { ... }
    fn write_all<'a>(&'a mut self, buf: &'a [u8]) -> WriteAll<'a, Self> 
       where Self: Unpin { ... }
    fn into_sink<Item>(self) -> IntoSink<Self, Item>
       where Item: AsRef<[u8]>,
             Self: Sized { ... }
}

An extension trait which adds utility methods to AsyncWrite types.

Provided Methods

fn flush(&mut self) -> Flush<'_, Self>

where Self: Unpin,

Creates a future which will entirely flush this AsyncWrite.

Examples

use futures::io::{AllowStdIo, AsyncWriteExt};
use std::io::{BufWriter, Cursor};

let mut output = vec![0u8; 5];

{
    let writer = Cursor::new(&mut output);
    let mut buffered = AllowStdIo::new(BufWriter::new(writer));
    buffered.write_all(&[1, 2]).await?;
    buffered.write_all(&[3, 4]).await?;
    buffered.flush().await?;
}

assert_eq!(output, [1, 2, 3, 4, 0]);

fn close(&mut self) -> Close<'_, Self>

where Self: Unpin,

Creates a future which will entirely close this AsyncWrite.

fn write<'a>(&'a mut self, buf: &'a [u8]) -> Write<'a, Self>

where Self: Unpin,

Creates a future which will write bytes from buf into the object.

The returned future will resolve to the number of bytes written once the write operation is completed.

fn write_vectored<'a>( &'a mut self, bufs: &'a [IoSlice<'a>], ) -> WriteVectored<'a, Self>

where Self: Unpin,

Creates a future which will write bytes from bufs into the object using vectored IO operations.

The returned future will resolve to the number of bytes written once the write operation is completed.

fn write_all<'a>(&'a mut self, buf: &'a [u8]) -> WriteAll<'a, Self>

where Self: Unpin,

Write data into this object.

Creates a future that will write the entire contents of the buffer buf into this AsyncWrite.

The returned future will not complete until all the data has been written.

Examples

use futures::io::{AsyncWriteExt, Cursor};

let mut writer = Cursor::new(vec![0u8; 5]);

writer.write_all(&[1, 2, 3, 4]).await?;

assert_eq!(writer.into_inner(), [1, 2, 3, 4, 0]);

fn into_sink<Item>(self) -> IntoSink<Self, Item>

where Item: AsRef<[u8]>, Self: Sized,

Allow using an AsyncWrite as a Sink<Item: AsRef<[u8]>>.

This adapter produces a sink that will write each value passed to it into the underlying writer.

Note that this function consumes the given writer, returning a wrapped version.

Examples

use futures::io::AsyncWriteExt;
use futures::stream::{self, StreamExt};

let stream = stream::iter(vec![Ok([1, 2, 3]), Ok([4, 5, 6])]);

let mut writer = vec![];

stream.forward((&mut writer).into_sink()).await?;

assert_eq!(writer, vec![1, 2, 3, 4, 5, 6]);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<W> AsyncWriteExt for W

where W: AsyncWrite + ?Sized,