Enum tokio_util::either::Either[][src]

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

Left(L)

Tuple Fields

0: L

Right(R)

Tuple Fields

0: R

Trait Implementations

Attempts to return the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to poll_read. Read more

Attempts to read from the AsyncRead into buf. Read more

Attempts to seek to an offset, in bytes, in a stream. Read more

Waits for a seek operation to complete. Read more

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

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

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

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

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

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

The type of value produced on completion.

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

Values yielded by the stream.

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted. Read more

Returns the bounds on the remaining length of the stream. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Reads all bytes into buf until the delimiter byte or EOF is reached. Read more

Reads all bytes until a newline (the 0xA byte) is reached, and append them to the provided buffer. Read more

Returns a stream of the contents of this reader split on the byte byte. Read more

Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read. Read more

Returns a stream over the lines of this reader. This method is the async equivalent to BufRead::lines. Read more

Creates a new AsyncRead instance that chains this stream with next. Read more

Pulls some bytes from this source into the specified buffer, returning how many bytes were read. Read more

Pulls some bytes from this source into the specified buffer, advancing the buffer’s internal cursor. Read more

Reads the exact number of bytes required to fill buf. Read more

Reads an unsigned 8 bit integer from the underlying reader. Read more

Reads a signed 8 bit integer from the underlying reader. Read more

Reads an unsigned 16-bit integer in big-endian order from the underlying reader. Read more

Reads a signed 16-bit integer in big-endian order from the underlying reader. Read more

Reads an unsigned 32-bit integer in big-endian order from the underlying reader. Read more

Reads a signed 32-bit integer in big-endian order from the underlying reader. Read more

Reads an unsigned 64-bit integer in big-endian order from the underlying reader. Read more

Reads an signed 64-bit integer in big-endian order from the underlying reader. Read more

Reads an unsigned 128-bit integer in big-endian order from the underlying reader. Read more

Reads an signed 128-bit integer in big-endian order from the underlying reader. Read more

Reads an 32-bit floating point type in big-endian order from the underlying reader. Read more

Reads an 64-bit floating point type in big-endian order from the underlying reader. Read more

Reads an unsigned 16-bit integer in little-endian order from the underlying reader. Read more

Reads a signed 16-bit integer in little-endian order from the underlying reader. Read more

Reads an unsigned 32-bit integer in little-endian order from the underlying reader. Read more

Reads a signed 32-bit integer in little-endian order from the underlying reader. Read more

Reads an unsigned 64-bit integer in little-endian order from the underlying reader. Read more

Reads an signed 64-bit integer in little-endian order from the underlying reader. Read more

Reads an unsigned 128-bit integer in little-endian order from the underlying reader. Read more

Reads an signed 128-bit integer in little-endian order from the underlying reader. Read more

Reads an 32-bit floating point type in little-endian order from the underlying reader. Read more

Reads an 64-bit floating point type in little-endian order from the underlying reader. Read more

Reads all bytes until EOF in this source, placing them into buf. Read more

Reads all bytes until EOF in this source, appending them to buf. Read more

Creates an adaptor which reads at most limit bytes from it. Read more

Creates a future which will seek an IO object, and then yield the new position in the object and the object itself. Read more

Creates a future which will rewind to the beginning of the stream. Read more

Creates a future which will return the current seek position from the start of the stream. Read more

Writes a buffer into this writer, returning how many bytes were written. Read more

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

Writes a buffer into this writer, advancing the buffer’s internal cursor. Read more

Attempts to write an entire buffer into this writer Read more

Attempts to write an entire buffer into this writer. Read more

Writes an unsigned 8-bit integer to the underlying writer. Read more

Writes an unsigned 8-bit integer to the underlying writer. Read more

Writes an unsigned 16-bit integer in big-endian order to the underlying writer. Read more

Writes a signed 16-bit integer in big-endian order to the underlying writer. Read more

Writes an unsigned 32-bit integer in big-endian order to the underlying writer. Read more

Writes a signed 32-bit integer in big-endian order to the underlying writer. Read more

Writes an unsigned 64-bit integer in big-endian order to the underlying writer. Read more

Writes an signed 64-bit integer in big-endian order to the underlying writer. Read more

Writes an unsigned 128-bit integer in big-endian order to the underlying writer. Read more

Writes an signed 128-bit integer in big-endian order to the underlying writer. Read more

Writes an 32-bit floating point type in big-endian order to the underlying writer. Read more

Writes an 64-bit floating point type in big-endian order to the underlying writer. Read more

Writes an unsigned 16-bit integer in little-endian order to the underlying writer. Read more

Writes a signed 16-bit integer in little-endian order to the underlying writer. Read more

Writes an unsigned 32-bit integer in little-endian order to the underlying writer. Read more

Writes a signed 32-bit integer in little-endian order to the underlying writer. Read more

Writes an unsigned 64-bit integer in little-endian order to the underlying writer. Read more

Writes an signed 64-bit integer in little-endian order to the underlying writer. Read more

Writes an unsigned 128-bit integer in little-endian order to the underlying writer. Read more

Writes an signed 128-bit integer in little-endian order to the underlying writer. Read more

Writes an 32-bit floating point type in little-endian order to the underlying writer. Read more

Writes an 64-bit floating point type in little-endian order to the underlying writer. Read more

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination. Read more

Shuts down the output stream, ensuring that the value can be dropped cleanly. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

🔬 This is a nightly-only experimental API. (into_future)

The output that the future will produce on completion.

🔬 This is a nightly-only experimental API. (into_future)

Which kind of future are we turning this into?

🔬 This is a nightly-only experimental API. (into_future)

Creates a future from a value.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type of successful values yielded by this future

The type of failures yielded by this future

Poll this TryFuture as if it were a Future. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type of successful values yielded by this future

The type of failures yielded by this future

Poll this TryStream as if it were a Stream. Read more