impl<T> Cursor<T>

fn new(inner: T) -> Self

Creates a new cursor wrapping the provided underlying in-memory buffer.

Cursor initial position is 0 even if underlying buffer (e.g., Vec) is not empty. So writing to cursor starts with overwriting Vec content, not with appending to it.

Examples

use futures::io::Cursor;

let buff = Cursor::new(Vec::new());
# fn force_inference(_: &Cursor<Vec<u8>>) {}
# force_inference(&buff);

fn into_inner(self) -> T

Consumes this cursor, returning the underlying value.

Examples

use futures::io::Cursor;

let buff = Cursor::new(Vec::new());
# fn force_inference(_: &Cursor<Vec<u8>>) {}
# force_inference(&buff);

let vec = buff.into_inner();

fn get_ref(&self) -> &T

Gets a reference to the underlying value in this cursor.

Examples

use futures::io::Cursor;

let buff = Cursor::new(Vec::new());
# fn force_inference(_: &Cursor<Vec<u8>>) {}
# force_inference(&buff);

let reference = buff.get_ref();

fn get_mut(&mut self) -> &mut T

Gets a mutable reference to the underlying value in this cursor.

Care should be taken to avoid modifying the internal I/O state of the underlying value as it may corrupt this cursor's position.

Examples

use futures::io::Cursor;

let mut buff = Cursor::new(Vec::new());
# fn force_inference(_: &Cursor<Vec<u8>>) {}
# force_inference(&buff);

let reference = buff.get_mut();

fn position(&self) -> u64

Returns the current position of this cursor.

Examples

# futures::executor::block_on(async {
use futures::io::{AsyncSeekExt, Cursor, SeekFrom};

let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);

assert_eq!(buff.position(), 0);

buff.seek(SeekFrom::Current(2)).await?;
assert_eq!(buff.position(), 2);

buff.seek(SeekFrom::Current(-1)).await?;
assert_eq!(buff.position(), 1);
# Ok::<(), Box<dyn std::error::Error>>(()) }).unwrap();

fn set_position(&mut self, pos: u64)

Sets the position of this cursor.

Examples

use futures::io::Cursor;

let mut buff = Cursor::new(vec![1, 2, 3, 4, 5]);

assert_eq!(buff.position(), 0);

buff.set_position(2);
assert_eq!(buff.position(), 2);

buff.set_position(4);
assert_eq!(buff.position(), 4);