Struct futures::io::Cursor[][src]

pub struct Cursor<T> { /* fields omitted */ }

A Cursor wraps an in-memory buffer and provides it with a AsyncSeek implementation.

Cursors are used with in-memory buffers, anything implementing AsRef<[u8]>, to allow them to implement AsyncRead and/or AsyncWrite, allowing these buffers to be used anywhere you might use a reader or writer that does actual I/O.

This library implements some I/O traits on various types which are commonly used as a buffer, like Cursor<Vec<u8>> and Cursor<&[u8]>.

Implementations

impl<T> Cursor<T>[src]

pub fn new(inner: T) -> Cursor<T>[src]

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());

pub fn into_inner(self) -> T[src]

Consumes this cursor, returning the underlying value.

Examples

use futures::io::Cursor;

let buff = Cursor::new(Vec::new());

let vec = buff.into_inner();

pub fn get_ref(&self) -> &T

Notable traits for &'_ mut F

impl<'_, F> Future for &'_ mut F where
    F: Future + Unpin + ?Sized
type Output = <F as Future>::Output;
[src]

Gets a reference to the underlying value in this cursor.

Examples

use futures::io::Cursor;

let buff = Cursor::new(Vec::new());

let reference = buff.get_ref();

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

Notable traits for &'_ mut F

impl<'_, F> Future for &'_ mut F where
    F: Future + Unpin + ?Sized
type Output = <F as Future>::Output;
[src]

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());

let reference = buff.get_mut();

pub fn position(&self) -> u64[src]

Returns the current position of this cursor.

Examples

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);

pub fn set_position(&mut self, pos: u64)[src]

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);

Trait Implementations

impl<T> AsyncBufRead for Cursor<T> where
    T: AsRef<[u8]> + Unpin
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impl<T> AsyncRead for Cursor<T> where
    T: AsRef<[u8]> + Unpin
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impl<T> AsyncSeek for Cursor<T> where
    T: AsRef<[u8]> + Unpin
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impl AsyncWrite for Cursor<Vec<u8, Global>>[src]

impl AsyncWrite for Cursor<Box<[u8], Global>>[src]

impl<'_> AsyncWrite for Cursor<&'_ mut Vec<u8, Global>>[src]

impl<'_> AsyncWrite for Cursor<&'_ mut [u8]>[src]

impl<T> Clone for Cursor<T> where
    T: Clone
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impl<T> Debug for Cursor<T> where
    T: Debug
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impl<T> Default for Cursor<T> where
    T: Default
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Auto Trait Implementations

impl<T> RefUnwindSafe for Cursor<T> where
    T: RefUnwindSafe

impl<T> Send for Cursor<T> where
    T: Send

impl<T> Sync for Cursor<T> where
    T: Sync

impl<T> Unpin for Cursor<T> where
    T: Unpin

impl<T> UnwindSafe for Cursor<T> where
    T: UnwindSafe

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
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impl<R> AsyncBufReadExt for R where
    R: AsyncBufRead + ?Sized
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impl<R> AsyncReadExt for R where
    R: AsyncRead + ?Sized
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impl<S> AsyncSeekExt for S where
    S: AsyncSeek + ?Sized
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impl<W> AsyncWriteExt for W where
    W: AsyncWrite + ?Sized
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impl<T> Borrow<T> for T where
    T: ?Sized
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impl<T> BorrowMut<T> for T where
    T: ?Sized
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impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
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impl<T> ToOwned for T where
    T: Clone
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type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
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type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.