[][src]Trait tokio::io::AsyncSeekExt

pub trait AsyncSeekExt: AsyncSeek {
    fn seek(&mut self, pos: SeekFrom) -> Seek<Self>
        Self: Unpin
, { ... } }

An extension trait which adds utility methods to AsyncSeek types.

As a convenience, this trait may be imported using the prelude:


use std::io::{Cursor, SeekFrom};
use tokio::prelude::*;

async fn main() -> io::Result<()> {
    let mut cursor = Cursor::new(b"abcdefg");

    // the `seek` method is defined by this trait

    let mut buf = [0; 1];
    let n = cursor.read(&mut buf).await?;
    assert_eq!(n, 1);
    assert_eq!(buf, [b'd']);


See module documentation for more details.

Provided methods

fn seek(&mut self, pos: SeekFrom) -> Seek<Self> where
    Self: Unpin

Creates a future which will seek an IO object, and then yield the new position in the object and the object itself.

In the case of an error the buffer and the object will be discarded, with the error yielded.


use tokio::fs::File;
use tokio::prelude::*;

use std::io::SeekFrom;

let mut file = File::open("foo.txt").await?;

let mut contents = vec![0u8; 10];
file.read_exact(&mut contents).await?;
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impl<S: AsyncSeek + ?Sized> AsyncSeekExt for S[src]

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