broker_tokio::io

Trait AsyncSeekExt

Source 
pub trait AsyncSeekExt: AsyncSeek {
    // Provided method
    fn seek(&mut self, pos: SeekFrom) -> Seek<'_, Self> ⓘ
       where Self: Unpin { ... }
}
Available on crate feature io-util only.
Expand description

An extension trait which adds utility methods to AsyncSeek types.

§Examples

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

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

    // the `seek` method is defined by this trait
    cursor.seek(SeekFrom::Start(3)).await?;

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

    Ok(())
}

Provided Methods§

Source

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.

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

use std::io::SeekFrom;

let mut file = File::open("foo.txt").await?;
file.seek(SeekFrom::Start(6)).await?;

let mut contents = vec![0u8; 10];
file.read_exact(&mut contents).await?;

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§