# tokio::io::Stderr - Rust
API documentation for the Rust `Stderr` struct in crate `tokio`.
Keywords: rust, rustlang, rust-lang, Stderr

# Struct tokio::io::Stderr [−] [src]

    pub struct Stderr { /* fields omitted */ }

A handle to the standard error stream of a process.

Concurrent writes to stderr must be executed with care: Only individual writes to this `AsyncWrite` are guaranteed to be intact. In particular you should be aware that writes using `write_all` are not guaranteed to occur as a single write, so multiple threads writing data with `write_all` may result in interleaved output.

Created by the `stderr` function.

# Examples

    use tokio::io::{self, AsyncWriteExt};

    #[tokio::main]
    async fn main() -> io::Result<()> {
        let mut stderr = io::stdout();
        stderr.write_all(b"Print some error here.").await?;
        Ok(())
    }

## Trait Implementations

### `impl AsRawFd for Stderr` [src]

#### `fn as_raw_fd(&self) -> RawFd` [src]

Extracts the raw file descriptor. Read more

### `impl AsyncWrite for Stderr` [src]

#### `fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8]
) -> Poll<Result<usize>>` [src]

Attempt to write bytes from `buf` into the object. Read more

#### `fn poll_flush(
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Result<(), Error>>` [src]

Attempts to flush the object, ensuring that any buffered data reach their destination. Read more

#### `fn poll_shutdown(
self: Pin<&mut Self>,
cx: &mut Context<'_>
) -> Poll<Result<(), Error>>` [src]

Initiates or attempts to shut down this writer, returning success when the I/O connection has completely shut down. Read more

#### `fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>]
) -> Poll<Result<usize, Error>>` [src]

Like `poll_write`, except that it writes from a slice of buffers. Read more

#### `fn is_write_vectored(&self) -> bool` [src]

Determines if this writer has an efficient `poll_write_vectored` implementation. Read more

### `impl Debug for Stderr` [src]

#### `fn fmt(&self, f: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

## Auto Trait Implementations

### `impl !RefUnwindSafe for Stderr` [src]

### `impl Send for Stderr` [src]

### `impl Sync for Stderr` [src]

### `impl Unpin for Stderr` [src]

### `impl !UnwindSafe for Stderr` [src]

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &Tⓘ

### Notable traits for &'_ mut F

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

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut Tⓘ

### Notable traits for &'_ mut F

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

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `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.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.