Enum tokio_util::either::Either
source · pub enum Either<L, R> {
Left(L),
Right(R),
}
Expand description
Combines two different futures, streams, or sinks having the same associated types into a single type.
This type implements common asynchronous traits such as Future
and those in Tokio.
§Example
The following code will not work:
ⓘ
#[tokio::main]
async fn main() {
let result = if some_condition() {
some_async_function()
} else {
other_async_function() // <- Will print: "`if` and `else` have incompatible types"
};
println!("Result is {}", result.await);
}
When the output type is the same, we can wrap each future in Either
to avoid the
issue:
use tokio_util::either::Either;
#[tokio::main]
async fn main() {
let result = if some_condition() {
Either::Left(some_async_function())
} else {
Either::Right(other_async_function())
};
let value = result.await;
println!("Result is {}", value);
}
Variants§
Trait Implementations§
source§impl<L, R> AsyncBufRead for Either<L, R>where
L: AsyncBufRead,
R: AsyncBufRead,
impl<L, R> AsyncBufRead for Either<L, R>where
L: AsyncBufRead,
R: AsyncBufRead,
source§impl<L, R> AsyncWrite for Either<L, R>where
L: AsyncWrite,
R: AsyncWrite,
impl<L, R> AsyncWrite for Either<L, R>where
L: AsyncWrite,
R: AsyncWrite,
source§fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize>>
fn poll_write( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize>>
Attempt to write bytes from
buf
into the object. Read moresource§fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>
Attempts to flush the object, ensuring that any buffered data reach
their destination. Read more
source§fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>
Initiates or attempts to shut down this writer, returning success when
the I/O connection has completely shut down. Read more
source§fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>],
) -> Poll<Result<usize, Error>>
fn poll_write_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>
Like
poll_write
, except that it writes from a slice of buffers. Read moresource§fn is_write_vectored(&self) -> bool
fn is_write_vectored(&self) -> bool
Determines if this writer has an efficient
poll_write_vectored
implementation. Read moresource§impl<L, R, Item, Error> Sink<Item> for Either<L, R>
impl<L, R, Item, Error> Sink<Item> for Either<L, R>
source§fn poll_ready(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Result<(), Self::Error>>
fn poll_ready( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<(), Self::Error>>
Attempts to prepare the
Sink
to receive a value. Read moresource§fn start_send(self: Pin<&mut Self>, item: Item) -> Result<(), Self::Error>
fn start_send(self: Pin<&mut Self>, item: Item) -> Result<(), Self::Error>
Begin the process of sending a value to the sink.
Each call to this function must be preceded by a successful call to
poll_ready
which returned Poll::Ready(Ok(()))
. Read moresource§impl<L, R> Stream for Either<L, R>
impl<L, R> Stream for Either<L, R>
Auto Trait Implementations§
impl<L, R> Freeze for Either<L, R>
impl<L, R> RefUnwindSafe for Either<L, R>where
L: RefUnwindSafe,
R: RefUnwindSafe,
impl<L, R> Send for Either<L, R>
impl<L, R> Sync for Either<L, R>
impl<L, R> Unpin for Either<L, R>
impl<L, R> UnwindSafe for Either<L, R>where
L: UnwindSafe,
R: UnwindSafe,
Blanket Implementations§
source§impl<R> AsyncBufReadExt for Rwhere
R: AsyncBufRead + ?Sized,
impl<R> AsyncBufReadExt for Rwhere
R: AsyncBufRead + ?Sized,
source§fn read_until<'a>(
&'a mut self,
byte: u8,
buf: &'a mut Vec<u8>,
) -> ReadUntil<'a, Self>where
Self: Unpin,
fn read_until<'a>(
&'a mut self,
byte: u8,
buf: &'a mut Vec<u8>,
) -> ReadUntil<'a, Self>where
Self: Unpin,
source§fn read_line<'a>(&'a mut self, buf: &'a mut String) -> ReadLine<'a, Self>where
Self: Unpin,
fn read_line<'a>(&'a mut self, buf: &'a mut String) -> ReadLine<'a, Self>where
Self: Unpin,
Reads all bytes until a newline (the 0xA byte) is reached, and append
them to the provided buffer. Read more
source§fn split(self, byte: u8) -> Split<Self>
fn split(self, byte: u8) -> Split<Self>
Returns a stream of the contents of this reader split on the byte
byte
. Read moresource§fn fill_buf(&mut self) -> FillBuf<'_, Self>where
Self: Unpin,
fn fill_buf(&mut self) -> FillBuf<'_, Self>where
Self: Unpin,
Returns the contents of the internal buffer, filling it with more
data from the inner reader if it is empty. Read more
source§impl<R> AsyncReadExt for R
impl<R> AsyncReadExt for R
source§fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Read<'a, Self>where
Self: Unpin,
fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> Read<'a, Self>where
Self: Unpin,
Pulls some bytes from this source into the specified buffer,
returning how many bytes were read. Read more
source§fn read_buf<'a, B>(&'a mut self, buf: &'a mut B) -> ReadBuf<'a, Self, B>
fn read_buf<'a, B>(&'a mut self, buf: &'a mut B) -> ReadBuf<'a, Self, B>
Pulls some bytes from this source into the specified buffer,
advancing the buffer’s internal cursor. Read more
source§fn read_exact<'a>(&'a mut self, buf: &'a mut [u8]) -> ReadExact<'a, Self>where
Self: Unpin,
fn read_exact<'a>(&'a mut self, buf: &'a mut [u8]) -> ReadExact<'a, Self>where
Self: Unpin,
Reads the exact number of bytes required to fill
buf
. Read moresource§fn read_u8(&mut self) -> ReadU8<&mut Self>where
Self: Unpin,
fn read_u8(&mut self) -> ReadU8<&mut Self>where
Self: Unpin,
Reads an unsigned 8 bit integer from the underlying reader. Read more
source§fn read_i8(&mut self) -> ReadI8<&mut Self>where
Self: Unpin,
fn read_i8(&mut self) -> ReadI8<&mut Self>where
Self: Unpin,
Reads a signed 8 bit integer from the underlying reader. Read more
source§fn read_u16(&mut self) -> ReadU16<&mut Self>where
Self: Unpin,
fn read_u16(&mut self) -> ReadU16<&mut Self>where
Self: Unpin,
Reads an unsigned 16-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_i16(&mut self) -> ReadI16<&mut Self>where
Self: Unpin,
fn read_i16(&mut self) -> ReadI16<&mut Self>where
Self: Unpin,
Reads a signed 16-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_u32(&mut self) -> ReadU32<&mut Self>where
Self: Unpin,
fn read_u32(&mut self) -> ReadU32<&mut Self>where
Self: Unpin,
Reads an unsigned 32-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_i32(&mut self) -> ReadI32<&mut Self>where
Self: Unpin,
fn read_i32(&mut self) -> ReadI32<&mut Self>where
Self: Unpin,
Reads a signed 32-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_u64(&mut self) -> ReadU64<&mut Self>where
Self: Unpin,
fn read_u64(&mut self) -> ReadU64<&mut Self>where
Self: Unpin,
Reads an unsigned 64-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_i64(&mut self) -> ReadI64<&mut Self>where
Self: Unpin,
fn read_i64(&mut self) -> ReadI64<&mut Self>where
Self: Unpin,
Reads an signed 64-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_u128(&mut self) -> ReadU128<&mut Self>where
Self: Unpin,
fn read_u128(&mut self) -> ReadU128<&mut Self>where
Self: Unpin,
Reads an unsigned 128-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_i128(&mut self) -> ReadI128<&mut Self>where
Self: Unpin,
fn read_i128(&mut self) -> ReadI128<&mut Self>where
Self: Unpin,
Reads an signed 128-bit integer in big-endian order from the
underlying reader. Read more
source§fn read_f32(&mut self) -> ReadF32<&mut Self>where
Self: Unpin,
fn read_f32(&mut self) -> ReadF32<&mut Self>where
Self: Unpin,
Reads an 32-bit floating point type in big-endian order from the
underlying reader. Read more
source§fn read_f64(&mut self) -> ReadF64<&mut Self>where
Self: Unpin,
fn read_f64(&mut self) -> ReadF64<&mut Self>where
Self: Unpin,
Reads an 64-bit floating point type in big-endian order from the
underlying reader. Read more
source§fn read_u16_le(&mut self) -> ReadU16Le<&mut Self>where
Self: Unpin,
fn read_u16_le(&mut self) -> ReadU16Le<&mut Self>where
Self: Unpin,
Reads an unsigned 16-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_i16_le(&mut self) -> ReadI16Le<&mut Self>where
Self: Unpin,
fn read_i16_le(&mut self) -> ReadI16Le<&mut Self>where
Self: Unpin,
Reads a signed 16-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_u32_le(&mut self) -> ReadU32Le<&mut Self>where
Self: Unpin,
fn read_u32_le(&mut self) -> ReadU32Le<&mut Self>where
Self: Unpin,
Reads an unsigned 32-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_i32_le(&mut self) -> ReadI32Le<&mut Self>where
Self: Unpin,
fn read_i32_le(&mut self) -> ReadI32Le<&mut Self>where
Self: Unpin,
Reads a signed 32-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_u64_le(&mut self) -> ReadU64Le<&mut Self>where
Self: Unpin,
fn read_u64_le(&mut self) -> ReadU64Le<&mut Self>where
Self: Unpin,
Reads an unsigned 64-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_i64_le(&mut self) -> ReadI64Le<&mut Self>where
Self: Unpin,
fn read_i64_le(&mut self) -> ReadI64Le<&mut Self>where
Self: Unpin,
Reads an signed 64-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_u128_le(&mut self) -> ReadU128Le<&mut Self>where
Self: Unpin,
fn read_u128_le(&mut self) -> ReadU128Le<&mut Self>where
Self: Unpin,
Reads an unsigned 128-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_i128_le(&mut self) -> ReadI128Le<&mut Self>where
Self: Unpin,
fn read_i128_le(&mut self) -> ReadI128Le<&mut Self>where
Self: Unpin,
Reads an signed 128-bit integer in little-endian order from the
underlying reader. Read more
source§fn read_f32_le(&mut self) -> ReadF32Le<&mut Self>where
Self: Unpin,
fn read_f32_le(&mut self) -> ReadF32Le<&mut Self>where
Self: Unpin,
Reads an 32-bit floating point type in little-endian order from the
underlying reader. Read more
source§fn read_f64_le(&mut self) -> ReadF64Le<&mut Self>where
Self: Unpin,
fn read_f64_le(&mut self) -> ReadF64Le<&mut Self>where
Self: Unpin,
Reads an 64-bit floating point type in little-endian order from the
underlying reader. Read more
source§fn read_to_end<'a>(&'a mut self, buf: &'a mut Vec<u8>) -> ReadToEnd<'a, Self>where
Self: Unpin,
fn read_to_end<'a>(&'a mut self, buf: &'a mut Vec<u8>) -> ReadToEnd<'a, Self>where
Self: Unpin,
Reads all bytes until EOF in this source, placing them into
buf
. Read moresource§impl<S> AsyncSeekExt for S
impl<S> AsyncSeekExt for S
source§fn seek(&mut self, pos: SeekFrom) -> Seek<'_, Self>where
Self: Unpin,
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. Read more
source§fn rewind(&mut self) -> Seek<'_, Self>where
Self: Unpin,
fn rewind(&mut self) -> Seek<'_, Self>where
Self: Unpin,
Creates a future which will rewind to the beginning of the stream. Read more
source§fn stream_position(&mut self) -> Seek<'_, Self>where
Self: Unpin,
fn stream_position(&mut self) -> Seek<'_, Self>where
Self: Unpin,
Creates a future which will return the current seek position from the
start of the stream. Read more
source§impl<W> AsyncWriteExt for Wwhere
W: AsyncWrite + ?Sized,
impl<W> AsyncWriteExt for Wwhere
W: AsyncWrite + ?Sized,
source§fn write<'a>(&'a mut self, src: &'a [u8]) -> Write<'a, Self>where
Self: Unpin,
fn write<'a>(&'a mut self, src: &'a [u8]) -> Write<'a, Self>where
Self: Unpin,
Writes a buffer into this writer, returning how many bytes were
written. Read more
source§fn write_vectored<'a, 'b>(
&'a mut self,
bufs: &'a [IoSlice<'b>],
) -> WriteVectored<'a, 'b, Self>where
Self: Unpin,
fn write_vectored<'a, 'b>(
&'a mut self,
bufs: &'a [IoSlice<'b>],
) -> WriteVectored<'a, 'b, Self>where
Self: Unpin,
source§fn write_buf<'a, B>(&'a mut self, src: &'a mut B) -> WriteBuf<'a, Self, B>
fn write_buf<'a, B>(&'a mut self, src: &'a mut B) -> WriteBuf<'a, Self, B>
Writes a buffer into this writer, advancing the buffer’s internal
cursor. Read more
source§fn write_all_buf<'a, B>(
&'a mut self,
src: &'a mut B,
) -> WriteAllBuf<'a, Self, B>
fn write_all_buf<'a, B>( &'a mut self, src: &'a mut B, ) -> WriteAllBuf<'a, Self, B>
Attempts to write an entire buffer into this writer. Read more
source§fn write_all<'a>(&'a mut self, src: &'a [u8]) -> WriteAll<'a, Self>where
Self: Unpin,
fn write_all<'a>(&'a mut self, src: &'a [u8]) -> WriteAll<'a, Self>where
Self: Unpin,
Attempts to write an entire buffer into this writer. Read more
source§fn write_u8(&mut self, n: u8) -> WriteU8<&mut Self>where
Self: Unpin,
fn write_u8(&mut self, n: u8) -> WriteU8<&mut Self>where
Self: Unpin,
Writes an unsigned 8-bit integer to the underlying writer. Read more
source§fn write_i8(&mut self, n: i8) -> WriteI8<&mut Self>where
Self: Unpin,
fn write_i8(&mut self, n: i8) -> WriteI8<&mut Self>where
Self: Unpin,
Writes a signed 8-bit integer to the underlying writer. Read more
source§fn write_u16(&mut self, n: u16) -> WriteU16<&mut Self>where
Self: Unpin,
fn write_u16(&mut self, n: u16) -> WriteU16<&mut Self>where
Self: Unpin,
Writes an unsigned 16-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_i16(&mut self, n: i16) -> WriteI16<&mut Self>where
Self: Unpin,
fn write_i16(&mut self, n: i16) -> WriteI16<&mut Self>where
Self: Unpin,
Writes a signed 16-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_u32(&mut self, n: u32) -> WriteU32<&mut Self>where
Self: Unpin,
fn write_u32(&mut self, n: u32) -> WriteU32<&mut Self>where
Self: Unpin,
Writes an unsigned 32-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_i32(&mut self, n: i32) -> WriteI32<&mut Self>where
Self: Unpin,
fn write_i32(&mut self, n: i32) -> WriteI32<&mut Self>where
Self: Unpin,
Writes a signed 32-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_u64(&mut self, n: u64) -> WriteU64<&mut Self>where
Self: Unpin,
fn write_u64(&mut self, n: u64) -> WriteU64<&mut Self>where
Self: Unpin,
Writes an unsigned 64-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_i64(&mut self, n: i64) -> WriteI64<&mut Self>where
Self: Unpin,
fn write_i64(&mut self, n: i64) -> WriteI64<&mut Self>where
Self: Unpin,
Writes an signed 64-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_u128(&mut self, n: u128) -> WriteU128<&mut Self>where
Self: Unpin,
fn write_u128(&mut self, n: u128) -> WriteU128<&mut Self>where
Self: Unpin,
Writes an unsigned 128-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_i128(&mut self, n: i128) -> WriteI128<&mut Self>where
Self: Unpin,
fn write_i128(&mut self, n: i128) -> WriteI128<&mut Self>where
Self: Unpin,
Writes an signed 128-bit integer in big-endian order to the
underlying writer. Read more
source§fn write_f32(&mut self, n: f32) -> WriteF32<&mut Self>where
Self: Unpin,
fn write_f32(&mut self, n: f32) -> WriteF32<&mut Self>where
Self: Unpin,
Writes an 32-bit floating point type in big-endian order to the
underlying writer. Read more
source§fn write_f64(&mut self, n: f64) -> WriteF64<&mut Self>where
Self: Unpin,
fn write_f64(&mut self, n: f64) -> WriteF64<&mut Self>where
Self: Unpin,
Writes an 64-bit floating point type in big-endian order to the
underlying writer. Read more
source§fn write_u16_le(&mut self, n: u16) -> WriteU16Le<&mut Self>where
Self: Unpin,
fn write_u16_le(&mut self, n: u16) -> WriteU16Le<&mut Self>where
Self: Unpin,
Writes an unsigned 16-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_i16_le(&mut self, n: i16) -> WriteI16Le<&mut Self>where
Self: Unpin,
fn write_i16_le(&mut self, n: i16) -> WriteI16Le<&mut Self>where
Self: Unpin,
Writes a signed 16-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_u32_le(&mut self, n: u32) -> WriteU32Le<&mut Self>where
Self: Unpin,
fn write_u32_le(&mut self, n: u32) -> WriteU32Le<&mut Self>where
Self: Unpin,
Writes an unsigned 32-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_i32_le(&mut self, n: i32) -> WriteI32Le<&mut Self>where
Self: Unpin,
fn write_i32_le(&mut self, n: i32) -> WriteI32Le<&mut Self>where
Self: Unpin,
Writes a signed 32-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_u64_le(&mut self, n: u64) -> WriteU64Le<&mut Self>where
Self: Unpin,
fn write_u64_le(&mut self, n: u64) -> WriteU64Le<&mut Self>where
Self: Unpin,
Writes an unsigned 64-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_i64_le(&mut self, n: i64) -> WriteI64Le<&mut Self>where
Self: Unpin,
fn write_i64_le(&mut self, n: i64) -> WriteI64Le<&mut Self>where
Self: Unpin,
Writes an signed 64-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_u128_le(&mut self, n: u128) -> WriteU128Le<&mut Self>where
Self: Unpin,
fn write_u128_le(&mut self, n: u128) -> WriteU128Le<&mut Self>where
Self: Unpin,
Writes an unsigned 128-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_i128_le(&mut self, n: i128) -> WriteI128Le<&mut Self>where
Self: Unpin,
fn write_i128_le(&mut self, n: i128) -> WriteI128Le<&mut Self>where
Self: Unpin,
Writes an signed 128-bit integer in little-endian order to the
underlying writer. Read more
source§fn write_f32_le(&mut self, n: f32) -> WriteF32Le<&mut Self>where
Self: Unpin,
fn write_f32_le(&mut self, n: f32) -> WriteF32Le<&mut Self>where
Self: Unpin,
Writes an 32-bit floating point type in little-endian order to the
underlying writer. Read more
source§fn write_f64_le(&mut self, n: f64) -> WriteF64Le<&mut Self>where
Self: Unpin,
fn write_f64_le(&mut self, n: f64) -> WriteF64Le<&mut Self>where
Self: Unpin,
Writes an 64-bit floating point type in little-endian order to the
underlying writer. Read more
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
🔬This is a nightly-only experimental API. (
clone_to_uninit
)source§impl<F> IntoFuture for Fwhere
F: Future,
impl<F> IntoFuture for Fwhere
F: Future,
source§type IntoFuture = F
type IntoFuture = F
Which kind of future are we turning this into?
source§fn into_future(self) -> <F as IntoFuture>::IntoFuture
fn into_future(self) -> <F as IntoFuture>::IntoFuture
Creates a future from a value. Read more
source§impl<T> TokioAsyncReadCompatExt for Twhere
T: AsyncRead,
impl<T> TokioAsyncReadCompatExt for Twhere
T: AsyncRead,
source§impl<T> TokioAsyncWriteCompatExt for Twhere
T: AsyncWrite,
impl<T> TokioAsyncWriteCompatExt for Twhere
T: AsyncWrite,
source§fn compat_write(self) -> Compat<Self>where
Self: Sized,
fn compat_write(self) -> Compat<Self>where
Self: Sized,
Wraps
self
with a compatibility layer that implements
futures_io::AsyncWrite
.