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    #![deny(unsafe_op_in_unsafe_fn)]

    #[cfg(all(test, not(target_os = "emscripten")))]
    mod tests;

    use crate::io::prelude::*;

    use crate::fmt;
    use crate::io::{self, Initializer, IoSlice, IoSliceMut};
    use crate::net::{Shutdown, SocketAddr, ToSocketAddrs};
    use crate::sys_common::net as net_imp;
    use crate::sys_common::{AsInner, FromInner, IntoInner};
    use crate::time::Duration;

    /// A TCP stream between a local and a remote socket.
    ///
    /// After creating a `TcpStream` by either [`connect`]ing to a remote host or
    /// [`accept`]ing 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].
    ///
    /// [`accept`]: TcpListener::accept
    /// [`connect`]: TcpStream::connect
    /// [IETF RFC 793]: https://tools.ietf.org/html/rfc793
    /// [reading]: Read
    /// [`shutdown`]: TcpStream::shutdown
    /// [writing]: Write
    ///
    /// # Examples
    ///
    /// ```no_run
    /// 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
    /// ```
    #[stable(feature = "rust1", since = "1.0.0")]
    pub struct TcpStream(net_imp::TcpStream);

    /// A TCP socket server, listening for connections.
    ///
    /// After creating a `TcpListener` by [`bind`]ing it to a socket address, it listens
    /// for incoming TCP connections. These can be accepted by calling [`accept`] or by
    /// iterating over the [`Incoming`] iterator returned by [`incoming`][`TcpListener::incoming`].
    ///
    /// The socket will be closed when the value is dropped.
    ///
    /// The Transmission Control Protocol is specified in [IETF RFC 793].
    ///
    /// [`accept`]: TcpListener::accept
    /// [`bind`]: TcpListener::bind
    /// [IETF RFC 793]: https://tools.ietf.org/html/rfc793
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::net::{TcpListener, TcpStream};
    ///
    /// fn handle_client(stream: TcpStream) {
    ///     // ...
    /// }
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = TcpListener::bind("127.0.0.1:80")?;
    ///
    ///     // accept connections and process them serially
    ///     for stream in listener.incoming() {
    ///         handle_client(stream?);
    ///     }
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "rust1", since = "1.0.0")]
    pub struct TcpListener(net_imp::TcpListener);

    /// An iterator that infinitely [`accept`]s connections on a [`TcpListener`].
    ///
    /// This `struct` is created by the [`TcpListener::incoming`] method.
    /// See its documentation for more.
    ///
    /// [`accept`]: TcpListener::accept
    #[stable(feature = "rust1", since = "1.0.0")]
    #[derive(Debug)]
    pub struct Incoming<'a> {
        listener: &'a TcpListener,
    }

    impl 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`:
        ///
        /// ```no_run
        /// 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...");
        /// }
        /// ```
        ///
        /// Open a TCP connection to `127.0.0.1:8080`. If the connection fails, open
        /// a TCP connection to `127.0.0.1:8081`:
        ///
        /// ```no_run
        /// 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...");
        /// }
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn connect<A: ToSocketAddrs>(addr: A) -> io::Result<TcpStream> {
            super::each_addr(addr, net_imp::TcpStream::connect).map(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.
        #[stable(feature = "tcpstream_connect_timeout", since = "1.21.0")]
        pub fn connect_timeout(addr: &SocketAddr, timeout: Duration) -> io::Result<TcpStream> {
            net_imp::TcpStream::connect_timeout(addr, timeout).map(TcpStream)
        }

        /// Returns the socket address of the remote peer of this TCP connection.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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)));
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn peer_addr(&self) -> io::Result<SocketAddr> {
            self.0.peer_addr()
        }

        /// Returns the socket address of the local half of this TCP connection.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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)));
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn local_addr(&self) -> io::Result<SocketAddr> {
            self.0.socket_addr()
        }

        /// 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
        ///
        /// ```no_run
        /// 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");
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
            self.0.shutdown(how)
        }

        /// 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
        ///
        /// ```no_run
        /// 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...");
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn try_clone(&self) -> io::Result<TcpStream> {
            self.0.duplicate().map(TcpStream)
        }

        /// 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`].
        ///
        /// [`read`]: Read::read
        /// [`WouldBlock`]: io::ErrorKind::WouldBlock
        /// [`TimedOut`]: io::ErrorKind::TimedOut
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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");
        /// ```
        ///
        /// An [`Err`] is returned if the zero [`Duration`] is passed to this
        /// method:
        ///
        /// ```no_run
        /// 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)
        /// ```
        #[stable(feature = "socket_timeout", since = "1.4.0")]
        pub fn set_read_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
            self.0.set_read_timeout(dur)
        }

        /// 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`].
        ///
        /// [`write`]: Write::write
        /// [`WouldBlock`]: io::ErrorKind::WouldBlock
        /// [`TimedOut`]: io::ErrorKind::TimedOut
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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");
        /// ```
        ///
        /// An [`Err`] is returned if the zero [`Duration`] is passed to this
        /// method:
        ///
        /// ```no_run
        /// 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)
        /// ```
        #[stable(feature = "socket_timeout", since = "1.4.0")]
        pub fn set_write_timeout(&self, dur: Option<Duration>) -> io::Result<()> {
            self.0.set_write_timeout(dur)
        }

        /// 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.
        ///
        /// [`read`]: Read::read
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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);
        /// ```
        #[stable(feature = "socket_timeout", since = "1.4.0")]
        pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
            self.0.read_timeout()
        }

        /// 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.
        ///
        /// [`write`]: Write::write
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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);
        /// ```
        #[stable(feature = "socket_timeout", since = "1.4.0")]
        pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
            self.0.write_timeout()
        }

        /// 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
        ///
        /// ```no_run
        /// use std::net::TcpStream;
        ///
        /// let stream = TcpStream::connect("127.0.0.1:8000")
        ///                        .expect("couldn't bind to address");
        /// let mut buf = [0; 10];
        /// let len = stream.peek(&mut buf).expect("peek failed");
        /// ```
        #[stable(feature = "peek", since = "1.18.0")]
        pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
            self.0.peek(buf)
        }

        /// 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
        ///
        /// ```no_run
        /// 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");
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
            self.0.set_nodelay(nodelay)
        }

        /// Gets the value of the `TCP_NODELAY` option on this socket.
        ///
        /// For more information about this option, see [`TcpStream::set_nodelay`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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);
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn nodelay(&self) -> io::Result<bool> {
            self.0.nodelay()
        }

        /// 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
        ///
        /// ```no_run
        /// 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");
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
            self.0.set_ttl(ttl)
        }

        /// Gets the value of the `IP_TTL` option for this socket.
        ///
        /// For more information about this option, see [`TcpStream::set_ttl`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// 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);
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn ttl(&self) -> io::Result<u32> {
            self.0.ttl()
        }

        /// 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
        ///
        /// ```no_run
        /// 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...");
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn take_error(&self) -> io::Result<Option<io::Error>> {
            self.0.take_error()
        }

        /// 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:
        ///
        /// ```no_run
        /// 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");
        ///
        /// # fn wait_for_fd() { unimplemented!() }
        /// 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);
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
            self.0.set_nonblocking(nonblocking)
        }
    }

    #[stable(feature = "rust1", since = "1.0.0")]
    impl Read for TcpStream {
        fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
            self.0.read(buf)
        }

        fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
            self.0.read_vectored(bufs)
        }

        #[inline]
        fn is_read_vectored(&self) -> bool {
            self.0.is_read_vectored()
        }

        #[inline]
        unsafe fn initializer(&self) -> Initializer {
            // SAFETY: Read is guaranteed to work on uninitialized memory
            unsafe { Initializer::nop() }
        }
    }
    #[stable(feature = "rust1", since = "1.0.0")]
    impl Write for TcpStream {
        fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
            self.0.write(buf)
        }

        fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
            self.0.write_vectored(bufs)
        }

        #[inline]
        fn is_write_vectored(&self) -> bool {
            self.0.is_write_vectored()
        }

        fn flush(&mut self) -> io::Result<()> {
            Ok(())
        }
    }
    #[stable(feature = "rust1", since = "1.0.0")]
    impl Read for &TcpStream {
        fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
            self.0.read(buf)
        }

        fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
            self.0.read_vectored(bufs)
        }

        #[inline]
        fn is_read_vectored(&self) -> bool {
            self.0.is_read_vectored()
        }

        #[inline]
        unsafe fn initializer(&self) -> Initializer {
            // SAFETY: Read is guaranteed to work on uninitialized memory
            unsafe { Initializer::nop() }
        }
    }
    #[stable(feature = "rust1", since = "1.0.0")]
    impl Write for &TcpStream {
        fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
            self.0.write(buf)
        }

        fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
            self.0.write_vectored(bufs)
        }

        #[inline]
        fn is_write_vectored(&self) -> bool {
            self.0.is_write_vectored()
        }

        fn flush(&mut self) -> io::Result<()> {
            Ok(())
        }
    }

    impl AsInner<net_imp::TcpStream> for TcpStream {
        fn as_inner(&self) -> &net_imp::TcpStream {
            &self.0
        }
    }

    impl FromInner<net_imp::TcpStream> for TcpStream {
        fn from_inner(inner: net_imp::TcpStream) -> TcpStream {
            TcpStream(inner)
        }
    }

    impl IntoInner<net_imp::TcpStream> for TcpStream {
        fn into_inner(self) -> net_imp::TcpStream {
            self.0
        }
    }

    #[stable(feature = "rust1", since = "1.0.0")]
    impl fmt::Debug for TcpStream {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            self.0.fmt(f)
        }
    }

    impl TcpListener {
        /// Creates a new `TcpListener` which will be bound to the specified
        /// address.
        ///
        /// The returned listener is ready for accepting connections.
        ///
        /// Binding with a port number of 0 will request that the OS assigns a port
        /// to this listener. The port allocated can be queried via the
        /// [`TcpListener::local_addr`] method.
        ///
        /// The address type can be any implementor of [`ToSocketAddrs`] trait. See
        /// its documentation for concrete examples.
        ///
        /// If `addr` yields multiple addresses, `bind` will be attempted with
        /// each of the addresses until one succeeds and returns the listener. If
        /// none of the addresses succeed in creating a listener, the error returned
        /// from the last attempt (the last address) is returned.
        ///
        /// # Examples
        ///
        /// Creates a TCP listener bound to `127.0.0.1:80`:
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
        /// ```
        ///
        /// Creates a TCP listener bound to `127.0.0.1:80`. If that fails, create a
        /// TCP listener bound to `127.0.0.1:443`:
        ///
        /// ```no_run
        /// use std::net::{SocketAddr, TcpListener};
        ///
        /// let addrs = [
        ///     SocketAddr::from(([127, 0, 0, 1], 80)),
        ///     SocketAddr::from(([127, 0, 0, 1], 443)),
        /// ];
        /// let listener = TcpListener::bind(&addrs[..]).unwrap();
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn bind<A: ToSocketAddrs>(addr: A) -> io::Result<TcpListener> {
            super::each_addr(addr, net_imp::TcpListener::bind).map(TcpListener)
        }

        /// Returns the local socket address of this listener.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpListener};
        ///
        /// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
        /// assert_eq!(listener.local_addr().unwrap(),
        ///            SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn local_addr(&self) -> io::Result<SocketAddr> {
            self.0.socket_addr()
        }

        /// Creates a new independently owned handle to the underlying socket.
        ///
        /// The returned [`TcpListener`] is a reference to the same socket that this
        /// object references. Both handles can be used to accept incoming
        /// connections and options set on one listener will affect the other.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
        /// let listener_clone = listener.try_clone().unwrap();
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn try_clone(&self) -> io::Result<TcpListener> {
            self.0.duplicate().map(TcpListener)
        }

        /// Accept a new incoming connection from this listener.
        ///
        /// This function will block the calling thread until a new TCP connection
        /// is established. When established, the corresponding [`TcpStream`] and the
        /// remote peer's address will be returned.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
        /// match listener.accept() {
        ///     Ok((_socket, addr)) => println!("new client: {:?}", addr),
        ///     Err(e) => println!("couldn't get client: {:?}", e),
        /// }
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
            // On WASM, `TcpStream` is uninhabited (as it's unsupported) and so
            // the `a` variable here is technically unused.
            #[cfg_attr(target_arch = "wasm32", allow(unused_variables))]
            self.0.accept().map(|(a, b)| (TcpStream(a), b))
        }

        /// Returns an iterator over the connections being received on this
        /// listener.
        ///
        /// The returned iterator will never return [`None`] and will also not yield
        /// the peer's [`SocketAddr`] structure. Iterating over it is equivalent to
        /// calling [`TcpListener::accept`] in a loop.
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
        ///
        /// for stream in listener.incoming() {
        ///     match stream {
        ///         Ok(stream) => {
        ///             println!("new client!");
        ///         }
        ///         Err(e) => { /* connection failed */ }
        ///     }
        /// }
        /// ```
        #[stable(feature = "rust1", since = "1.0.0")]
        pub fn incoming(&self) -> Incoming<'_> {
            Incoming { listener: self }
        }

        /// 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
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
        /// listener.set_ttl(100).expect("could not set TTL");
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
            self.0.set_ttl(ttl)
        }

        /// Gets the value of the `IP_TTL` option for this socket.
        ///
        /// For more information about this option, see [`TcpListener::set_ttl`].
        ///
        /// # Examples
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
        /// listener.set_ttl(100).expect("could not set TTL");
        /// assert_eq!(listener.ttl().unwrap_or(0), 100);
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn ttl(&self) -> io::Result<u32> {
            self.0.ttl()
        }

        #[stable(feature = "net2_mutators", since = "1.9.0")]
        #[rustc_deprecated(
            since = "1.16.0",
            reason = "this option can only be set before the socket is bound"
        )]
        #[allow(missing_docs)]
        pub fn set_only_v6(&self, only_v6: bool) -> io::Result<()> {
            self.0.set_only_v6(only_v6)
        }

        #[stable(feature = "net2_mutators", since = "1.9.0")]
        #[rustc_deprecated(
            since = "1.16.0",
            reason = "this option can only be set before the socket is bound"
        )]
        #[allow(missing_docs)]
        pub fn only_v6(&self) -> io::Result<bool> {
            self.0.only_v6()
        }

        /// 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
        ///
        /// ```no_run
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:80").unwrap();
        /// listener.take_error().expect("No error was expected");
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn take_error(&self) -> io::Result<Option<io::Error>> {
            self.0.take_error()
        }

        /// Moves this TCP stream into or out of nonblocking mode.
        ///
        /// This will result in the `accept` operation 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
        ///
        /// Bind a TCP listener to an address, listen for connections, and read
        /// bytes in nonblocking mode:
        ///
        /// ```no_run
        /// use std::io;
        /// use std::net::TcpListener;
        ///
        /// let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
        /// listener.set_nonblocking(true).expect("Cannot set non-blocking");
        ///
        /// # fn wait_for_fd() { unimplemented!() }
        /// # fn handle_connection(stream: std::net::TcpStream) { unimplemented!() }
        /// for stream in listener.incoming() {
        ///     match stream {
        ///         Ok(s) => {
        ///             // do something with the TcpStream
        ///             handle_connection(s);
        ///         }
        ///         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();
        ///             continue;
        ///         }
        ///         Err(e) => panic!("encountered IO error: {}", e),
        ///     }
        /// }
        /// ```
        #[stable(feature = "net2_mutators", since = "1.9.0")]
        pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
            self.0.set_nonblocking(nonblocking)
        }
    }

    #[stable(feature = "rust1", since = "1.0.0")]
    impl<'a> Iterator for Incoming<'a> {
        type Item = io::Result<TcpStream>;
        fn next(&mut self) -> Option<io::Result<TcpStream>> {
            Some(self.listener.accept().map(|p| p.0))
        }
    }

    impl AsInner<net_imp::TcpListener> for TcpListener {
        fn as_inner(&self) -> &net_imp::TcpListener {
            &self.0
        }
    }

    impl FromInner<net_imp::TcpListener> for TcpListener {
        fn from_inner(inner: net_imp::TcpListener) -> TcpListener {
            TcpListener(inner)
        }
    }

    impl IntoInner<net_imp::TcpListener> for TcpListener {
        fn into_inner(self) -> net_imp::TcpListener {
            self.0
        }
    }

    #[stable(feature = "rust1", since = "1.0.0")]
    impl fmt::Debug for TcpListener {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            self.0.fmt(f)
        }
    }