Struct std::net::TcpStream

1.0.0 · source ·
pub struct TcpStream(/* private fields */);
Expand description

A TCP stream between a local and a remote socket.

After creating a TcpStream by either connecting to a remote host or accepting a connection on a TcpListener, data can be transmitted by reading and writing to it.

The connection will be closed when the value is dropped. The reading and writing portions of the connection can also be shut down individually with the shutdown method.

The Transmission Control Protocol is specified in IETF RFC 793.

Examples

use std::io::prelude::*;
use std::net::TcpStream;

fn main() -> std::io::Result<()> {
    let mut stream = TcpStream::connect("127.0.0.1:34254")?;

    stream.write(&[1])?;
    stream.read(&mut [0; 128])?;
    Ok(())
} // the stream is closed here
Run

Implementations§

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impl TcpStream

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pub fn connect<A: ToSocketAddrs>(addr: A) -> Result<TcpStream>

Opens a TCP connection to a remote host.

addr is an address of the remote host. Anything which implements ToSocketAddrs trait can be supplied for the address; see this trait documentation for concrete examples.

If addr yields multiple addresses, connect will be attempted with each of the addresses until a connection is successful. If none of the addresses result in a successful connection, the error returned from the last connection attempt (the last address) is returned.

Examples

Open a TCP connection to 127.0.0.1:8080:

use std::net::TcpStream;

if let Ok(stream) = TcpStream::connect("127.0.0.1:8080") {
    println!("Connected to the server!");
} else {
    println!("Couldn't connect to server...");
}
Run

Open a TCP connection to 127.0.0.1:8080. If the connection fails, open a TCP connection to 127.0.0.1:8081:

use std::net::{SocketAddr, TcpStream};

let addrs = [
    SocketAddr::from(([127, 0, 0, 1], 8080)),
    SocketAddr::from(([127, 0, 0, 1], 8081)),
];
if let Ok(stream) = TcpStream::connect(&addrs[..]) {
    println!("Connected to the server!");
} else {
    println!("Couldn't connect to server...");
}
Run
1.21.0 · source

pub fn connect_timeout( addr: &SocketAddr, timeout: Duration ) -> Result<TcpStream>

Opens a TCP connection to a remote host with a timeout.

Unlike connect, connect_timeout takes a single SocketAddr since timeout must be applied to individual addresses.

It is an error to pass a zero Duration to this function.

Unlike other methods on TcpStream, this does not correspond to a single system call. It instead calls connect in nonblocking mode and then uses an OS-specific mechanism to await the completion of the connection request.

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pub fn peer_addr(&self) -> Result<SocketAddr>

Returns the socket address of the remote peer of this TCP connection.

Examples
use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpStream};

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
assert_eq!(stream.peer_addr().unwrap(),
           SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
Run
source

pub fn local_addr(&self) -> Result<SocketAddr>

Returns the socket address of the local half of this TCP connection.

Examples
use std::net::{IpAddr, Ipv4Addr, TcpStream};

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
assert_eq!(stream.local_addr().unwrap().ip(),
           IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)));
Run
source

pub fn shutdown(&self, how: Shutdown) -> Result<()>

Shuts down the read, write, or both halves of this connection.

This function will cause all pending and future I/O on the specified portions to return immediately with an appropriate value (see the documentation of Shutdown).

Platform-specific behavior

Calling this function multiple times may result in different behavior, depending on the operating system. On Linux, the second call will return Ok(()), but on macOS, it will return ErrorKind::NotConnected. This may change in the future.

Examples
use std::net::{Shutdown, TcpStream};

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.shutdown(Shutdown::Both).expect("shutdown call failed");
Run
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pub fn try_clone(&self) -> Result<TcpStream>

Creates a new independently owned handle to the underlying socket.

The returned TcpStream is a reference to the same stream that this object references. Both handles will read and write the same stream of data, and options set on one stream will be propagated to the other stream.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
let stream_clone = stream.try_clone().expect("clone failed...");
Run
1.4.0 · source

pub fn set_read_timeout(&self, dur: Option<Duration>) -> Result<()>

Sets the read timeout to the timeout specified.

If the value specified is None, then read calls will block indefinitely. An Err is returned if the zero Duration is passed to this method.

Platform-specific behavior

Platforms may return a different error code whenever a read times out as a result of setting this option. For example Unix typically returns an error of the kind WouldBlock, but Windows may return TimedOut.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_read_timeout(None).expect("set_read_timeout call failed");
Run

An Err is returned if the zero Duration is passed to this method:

use std::io;
use std::net::TcpStream;
use std::time::Duration;

let stream = TcpStream::connect("127.0.0.1:8080").unwrap();
let result = stream.set_read_timeout(Some(Duration::new(0, 0)));
let err = result.unwrap_err();
assert_eq!(err.kind(), io::ErrorKind::InvalidInput)
Run
1.4.0 · source

pub fn set_write_timeout(&self, dur: Option<Duration>) -> Result<()>

Sets the write timeout to the timeout specified.

If the value specified is None, then write calls will block indefinitely. An Err is returned if the zero Duration is passed to this method.

Platform-specific behavior

Platforms may return a different error code whenever a write times out as a result of setting this option. For example Unix typically returns an error of the kind WouldBlock, but Windows may return TimedOut.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_write_timeout(None).expect("set_write_timeout call failed");
Run

An Err is returned if the zero Duration is passed to this method:

use std::io;
use std::net::TcpStream;
use std::time::Duration;

let stream = TcpStream::connect("127.0.0.1:8080").unwrap();
let result = stream.set_write_timeout(Some(Duration::new(0, 0)));
let err = result.unwrap_err();
assert_eq!(err.kind(), io::ErrorKind::InvalidInput)
Run
1.4.0 · source

pub fn read_timeout(&self) -> Result<Option<Duration>>

Returns the read timeout of this socket.

If the timeout is None, then read calls will block indefinitely.

Platform-specific behavior

Some platforms do not provide access to the current timeout.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_read_timeout(None).expect("set_read_timeout call failed");
assert_eq!(stream.read_timeout().unwrap(), None);
Run
1.4.0 · source

pub fn write_timeout(&self) -> Result<Option<Duration>>

Returns the write timeout of this socket.

If the timeout is None, then write calls will block indefinitely.

Platform-specific behavior

Some platforms do not provide access to the current timeout.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_write_timeout(None).expect("set_write_timeout call failed");
assert_eq!(stream.write_timeout().unwrap(), None);
Run
1.18.0 · source

pub fn peek(&self, buf: &mut [u8]) -> Result<usize>

Receives data on the socket from the remote address to which it is connected, without removing that data from the queue. On success, returns the number of bytes peeked.

Successive calls return the same data. This is accomplished by passing MSG_PEEK as a flag to the underlying recv system call.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8000")
                       .expect("Couldn't connect to the server...");
let mut buf = [0; 10];
let len = stream.peek(&mut buf).expect("peek failed");
Run
source

pub fn set_linger(&self, linger: Option<Duration>) -> Result<()>

🔬This is a nightly-only experimental API. (tcp_linger #88494)

Sets the value of the SO_LINGER option on this socket.

This value controls how the socket is closed when data remains to be sent. If SO_LINGER is set, the socket will remain open for the specified duration as the system attempts to send pending data. Otherwise, the system may close the socket immediately, or wait for a default timeout.

Examples
#![feature(tcp_linger)]

use std::net::TcpStream;
use std::time::Duration;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_linger(Some(Duration::from_secs(0))).expect("set_linger call failed");
Run
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pub fn linger(&self) -> Result<Option<Duration>>

🔬This is a nightly-only experimental API. (tcp_linger #88494)

Gets the value of the SO_LINGER option on this socket.

For more information about this option, see TcpStream::set_linger.

Examples
#![feature(tcp_linger)]

use std::net::TcpStream;
use std::time::Duration;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_linger(Some(Duration::from_secs(0))).expect("set_linger call failed");
assert_eq!(stream.linger().unwrap(), Some(Duration::from_secs(0)));
Run
1.9.0 · source

pub fn set_nodelay(&self, nodelay: bool) -> Result<()>

Sets the value of the TCP_NODELAY option on this socket.

If set, this option disables the Nagle algorithm. This means that segments are always sent as soon as possible, even if there is only a small amount of data. When not set, data is buffered until there is a sufficient amount to send out, thereby avoiding the frequent sending of small packets.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_nodelay(true).expect("set_nodelay call failed");
Run
1.9.0 · source

pub fn nodelay(&self) -> Result<bool>

Gets the value of the TCP_NODELAY option on this socket.

For more information about this option, see TcpStream::set_nodelay.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_nodelay(true).expect("set_nodelay call failed");
assert_eq!(stream.nodelay().unwrap_or(false), true);
Run
1.9.0 · source

pub fn set_ttl(&self, ttl: u32) -> Result<()>

Sets the value for the IP_TTL option on this socket.

This value sets the time-to-live field that is used in every packet sent from this socket.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_ttl(100).expect("set_ttl call failed");
Run
1.9.0 · source

pub fn ttl(&self) -> Result<u32>

Gets the value of the IP_TTL option for this socket.

For more information about this option, see TcpStream::set_ttl.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.set_ttl(100).expect("set_ttl call failed");
assert_eq!(stream.ttl().unwrap_or(0), 100);
Run
1.9.0 · source

pub fn take_error(&self) -> Result<Option<Error>>

Gets the value of the SO_ERROR option on this socket.

This will retrieve the stored error in the underlying socket, clearing the field in the process. This can be useful for checking errors between calls.

Examples
use std::net::TcpStream;

let stream = TcpStream::connect("127.0.0.1:8080")
                       .expect("Couldn't connect to the server...");
stream.take_error().expect("No error was expected...");
Run
1.9.0 · source

pub fn set_nonblocking(&self, nonblocking: bool) -> Result<()>

Moves this TCP stream into or out of nonblocking mode.

This will result in read, write, recv and send operations becoming nonblocking, i.e., immediately returning from their calls. If the IO operation is successful, Ok is returned and no further action is required. If the IO operation could not be completed and needs to be retried, an error with kind io::ErrorKind::WouldBlock is returned.

On Unix platforms, calling this method corresponds to calling fcntl FIONBIO. On Windows calling this method corresponds to calling ioctlsocket FIONBIO.

Examples

Reading bytes from a TCP stream in non-blocking mode:

use std::io::{self, Read};
use std::net::TcpStream;

let mut stream = TcpStream::connect("127.0.0.1:7878")
    .expect("Couldn't connect to the server...");
stream.set_nonblocking(true).expect("set_nonblocking call failed");

let mut buf = vec![];
loop {
    match stream.read_to_end(&mut buf) {
        Ok(_) => break,
        Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
            // wait until network socket is ready, typically implemented
            // via platform-specific APIs such as epoll or IOCP
            wait_for_fd();
        }
        Err(e) => panic!("encountered IO error: {e}"),
    };
};
println!("bytes: {buf:?}");
Run

Trait Implementations§

1.63.0 · source§

impl AsFd for TcpStream

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fn as_fd(&self) -> BorrowedFd<'_>

Borrows the file descriptor. Read more
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impl AsRawFd for TcpStream

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fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor. Read more
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impl AsRawSocket for TcpStream

Available on Windows only.
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fn as_raw_socket(&self) -> RawSocket

Extracts the raw socket. Read more
1.63.0 · source§

impl AsSocket for TcpStream

Available on Windows only.
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fn as_socket(&self) -> BorrowedSocket<'_>

Borrows the socket.
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impl Debug for TcpStream

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
1.63.0 · source§

impl From<OwnedFd> for TcpStream

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fn from(owned_fd: OwnedFd) -> Self

Converts to this type from the input type.
1.63.0 · source§

impl From<OwnedSocket> for TcpStream

Available on Windows only.
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fn from(owned: OwnedSocket) -> Self

Converts to this type from the input type.
1.63.0 · source§

impl From<TcpStream> for OwnedFd

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fn from(tcp_stream: TcpStream) -> OwnedFd

Converts to this type from the input type.
1.63.0 · source§

impl From<TcpStream> for OwnedSocket

Available on Windows only.
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fn from(tcp_stream: TcpStream) -> OwnedSocket

Converts to this type from the input type.
1.1.0 · source§

impl FromRawFd for TcpStream

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unsafe fn from_raw_fd(fd: RawFd) -> TcpStream

Constructs a new instance of Self from the given raw file descriptor. Read more
1.1.0 · source§

impl FromRawSocket for TcpStream

Available on Windows only.
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unsafe fn from_raw_socket(sock: RawSocket) -> TcpStream

Constructs a new I/O object from the specified raw socket. Read more
1.4.0 · source§

impl IntoRawFd for TcpStream

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fn into_raw_fd(self) -> RawFd

Consumes this object, returning the raw underlying file descriptor. Read more
1.4.0 · source§

impl IntoRawSocket for TcpStream

Available on Windows only.
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fn into_raw_socket(self) -> RawSocket

Consumes this object, returning the raw underlying socket. Read more
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impl Read for &TcpStream

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fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
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fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)
Pull some bytes from this source into the specified buffer. Read more
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fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>

Like read, except that it reads into a slice of buffers. Read more
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fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)
Determines if this Reader has an efficient read_vectored implementation. Read more
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fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>

Read all bytes until EOF in this source, placing them into buf. Read more
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fn read_to_string(&mut self, buf: &mut String) -> Result<usize>

Read all bytes until EOF in this source, appending them to buf. Read more
1.6.0 · source§

fn read_exact(&mut self, buf: &mut [u8]) -> Result<()>

Read the exact number of bytes required to fill buf. Read more
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fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)
Read the exact number of bytes required to fill cursor. Read more
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fn by_ref(&mut self) -> &mut Selfwhere Self: Sized,

Creates a “by reference” adaptor for this instance of Read. Read more
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fn bytes(self) -> Bytes<Self> where Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more
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fn chain<R: Read>(self, next: R) -> Chain<Self, R> where Self: Sized,

Creates an adapter which will chain this stream with another. Read more
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fn take(self, limit: u64) -> Take<Self> where Self: Sized,

Creates an adapter which will read at most limit bytes from it. Read more
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impl Read for TcpStream

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fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
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fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)
Pull some bytes from this source into the specified buffer. Read more
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fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize>

Like read, except that it reads into a slice of buffers. Read more
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fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)
Determines if this Reader has an efficient read_vectored implementation. Read more
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fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize>

Read all bytes until EOF in this source, placing them into buf. Read more
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fn read_to_string(&mut self, buf: &mut String) -> Result<usize>

Read all bytes until EOF in this source, appending them to buf. Read more
1.6.0 · source§

fn read_exact(&mut self, buf: &mut [u8]) -> Result<()>

Read the exact number of bytes required to fill buf. Read more
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fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<()>

🔬This is a nightly-only experimental API. (read_buf #78485)
Read the exact number of bytes required to fill cursor. Read more
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fn by_ref(&mut self) -> &mut Selfwhere Self: Sized,

Creates a “by reference” adaptor for this instance of Read. Read more
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fn bytes(self) -> Bytes<Self> where Self: Sized,

Transforms this Read instance to an Iterator over its bytes. Read more
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fn chain<R: Read>(self, next: R) -> Chain<Self, R> where Self: Sized,

Creates an adapter which will chain this stream with another. Read more
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fn take(self, limit: u64) -> Take<Self> where Self: Sized,

Creates an adapter which will read at most limit bytes from it. Read more
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impl TcpStreamExt for TcpStream

Available on Linux or Android only.
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fn set_quickack(&self, quickack: bool) -> Result<()>

🔬This is a nightly-only experimental API. (tcp_quickack #96256)
Available on Linux only.
Enable or disable TCP_QUICKACK. Read more
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fn quickack(&self) -> Result<bool>

🔬This is a nightly-only experimental API. (tcp_quickack #96256)
Available on Linux only.
Gets the value of the TCP_QUICKACK option on this socket. Read more
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impl Write for &TcpStream

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fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this writer, returning how many bytes were written. Read more
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fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers. Read more
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fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)
Determines if this Writer has an efficient write_vectored implementation. Read more
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fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
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fn write_all(&mut self, buf: &[u8]) -> Result<()>

Attempts to write an entire buffer into this writer. Read more
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fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<()>

🔬This is a nightly-only experimental API. (write_all_vectored #70436)
Attempts to write multiple buffers into this writer. Read more
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fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<()>

Writes a formatted string into this writer, returning any error encountered. Read more
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fn by_ref(&mut self) -> &mut Selfwhere Self: Sized,

Creates a “by reference” adapter for this instance of Write. Read more
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impl Write for TcpStream

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fn write(&mut self, buf: &[u8]) -> Result<usize>

Write a buffer into this writer, returning how many bytes were written. Read more
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fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers. Read more
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fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector #69941)
Determines if this Writer has an efficient write_vectored implementation. Read more
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fn flush(&mut self) -> Result<()>

Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
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fn write_all(&mut self, buf: &[u8]) -> Result<()>

Attempts to write an entire buffer into this writer. Read more
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fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<()>

🔬This is a nightly-only experimental API. (write_all_vectored #70436)
Attempts to write multiple buffers into this writer. Read more
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fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<()>

Writes a formatted string into this writer, returning any error encountered. Read more
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fn by_ref(&mut self) -> &mut Selfwhere Self: Sized,

Creates a “by reference” adapter for this instance of Write. Read more

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.