Remove TcpSocket type

The socket2 crate provide all the functionality and more. Furthermore
supporting all socket options is beyond the scope of Mio.

The easier migration is to the socket2 crate, using the Socket or
SockRef types.

The migration for Tokio is tracked in
tokio-rs/tokio#4135.

Cargo.toml

@@ -47,7 +47,7 @@ libc = "0.2.86"
 
 [target.'cfg(windows)'.dependencies]
 miow   = "0.3.6"
-winapi = { version = "0.3", features = ["winsock2", "mswsock", "mstcpip"] }
+winapi = { version = "0.3", features = ["winsock2", "mswsock"] }
 ntapi  = "0.3"
 
 [dev-dependencies]

src/net/mod.rs

@@ -8,7 +8,7 @@
 //! [portability guidelines]: ../struct.Poll.html#portability
 
 mod tcp;
-pub use self::tcp::{TcpKeepalive, TcpListener, TcpSocket, TcpStream};
+pub use self::tcp::{TcpListener, TcpStream};
 
 mod udp;
 pub use self::udp::UdpSocket;

src/net/tcp/listener.rs

@@ -5,8 +5,11 @@ use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
 use std::os::windows::io::{AsRawSocket, FromRawSocket, IntoRawSocket, RawSocket};
 use std::{fmt, io};
 
-use super::{TcpSocket, TcpStream};
 use crate::io_source::IoSource;
+use crate::net::TcpStream;
+#[cfg(unix)]
+use crate::sys::tcp::set_reuseaddr;
+use crate::sys::tcp::{bind, listen, new_for_addr};
 use crate::{event, sys, Interest, Registry, Token};
 
 /// A structure representing a socket server
@@ -50,7 +53,11 @@ impl TcpListener {
     /// 3. Bind the socket to the specified address.
     /// 4. Calls `listen` on the socket to prepare it to receive new connections.
     pub fn bind(addr: SocketAddr) -> io::Result<TcpListener> {
-        let socket = TcpSocket::new_for_addr(addr)?;
+        let socket = new_for_addr(addr)?;
+        #[cfg(unix)]
+        let listener = unsafe { TcpListener::from_raw_fd(socket) };
+        #[cfg(windows)]
+        let listener = unsafe { TcpListener::from_raw_socket(socket as _) };
 
         // On platforms with Berkeley-derived sockets, this allows to quickly
         // rebind a socket, without needing to wait for the OS to clean up the
@@ -60,10 +67,11 @@ impl TcpListener {
         // which allows “socket hijacking”, so we explicitly don't set it here.
         // https://docs.microsoft.com/en-us/windows/win32/winsock/using-so-reuseaddr-and-so-exclusiveaddruse
         #[cfg(not(windows))]
-        socket.set_reuseaddr(true)?;
+        set_reuseaddr(&listener.inner, true)?;
 
-        socket.bind(addr)?;
-        socket.listen(1024)
+        bind(&listener.inner, addr)?;
+        listen(&listener.inner, 1024)?;
+        Ok(listener)
     }
 
     /// Creates a new `TcpListener` from a standard `net::TcpListener`.

src/net/tcp/mod.rs

@@ -1,8 +1,5 @@
 mod listener;
 pub use self::listener::TcpListener;
 
-mod socket;
-pub use self::socket::{TcpKeepalive, TcpSocket};
-
 mod stream;
 pub use self::stream::TcpStream;