Fix various Clippy lints

examples/tcp_listenfd_server.rs

@@ -125,6 +125,7 @@ fn next(current: &mut Token) -> Token {
 }
 
 /// Returns `true` if the connection is done.
+#[allow(clippy::unused_io_amount)]
 fn handle_connection_event(
     registry: &Registry,
     connection: &mut TcpStream,

src/sys/unix/selector/epoll.rs

@@ -5,7 +5,7 @@ use std::os::unix::io::{AsRawFd, RawFd};
 #[cfg(debug_assertions)]
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::time::Duration;
-use std::{cmp, i32, io, ptr};
+use std::{cmp, io, ptr};
 
 /// Unique id for use as `SelectorId`.
 #[cfg(debug_assertions)]
@@ -77,7 +77,7 @@ impl Selector {
         #[cfg(target_pointer_width = "32")]
         const MAX_SAFE_TIMEOUT: u128 = 1789569;
         #[cfg(not(target_pointer_width = "32"))]
-        const MAX_SAFE_TIMEOUT: u128 = libc::c_int::max_value() as u128;
+        const MAX_SAFE_TIMEOUT: u128 = libc::c_int::MAX as u128;
 
         let timeout = timeout
             .map(|to| {

src/sys/unix/selector/kqueue.rs

@@ -92,7 +92,7 @@ impl Selector {
 
     pub fn select(&self, events: &mut Events, timeout: Option<Duration>) -> io::Result<()> {
         let timeout = timeout.map(|to| libc::timespec {
-            tv_sec: cmp::min(to.as_secs(), libc::time_t::max_value() as u64) as libc::time_t,
+            tv_sec: cmp::min(to.as_secs(), libc::time_t::MAX as u64) as libc::time_t,
             // `Duration::subsec_nanos` is guaranteed to be less than one
             // billion (the number of nanoseconds in a second), making the
             // cast to i32 safe. The cast itself is needed for platforms

src/sys/unix/selector/poll.rs

@@ -504,7 +504,7 @@ fn poll(fds: &mut [PollFd], timeout: Option<Duration>) -> io::Result<usize> {
         #[cfg(target_pointer_width = "32")]
         const MAX_SAFE_TIMEOUT: u128 = 1789569;
         #[cfg(not(target_pointer_width = "32"))]
-        const MAX_SAFE_TIMEOUT: u128 = libc::c_int::max_value() as u128;
+        const MAX_SAFE_TIMEOUT: u128 = libc::c_int::MAX as u128;
 
         let timeout = timeout
             .map(|to| {

src/sys/unix/tcp.rs

@@ -34,7 +34,7 @@ pub(crate) fn connect(socket: &net::TcpStream, addr: SocketAddr) -> io::Result<(
 }
 
 pub(crate) fn listen(socket: &net::TcpListener, backlog: u32) -> io::Result<()> {
-    let backlog = backlog.try_into().unwrap_or(i32::max_value());
+    let backlog = backlog.try_into().unwrap_or(i32::MAX);
     syscall!(listen(socket.as_raw_fd(), backlog))?;
     Ok(())
 }

src/sys/unix/waker.rs

@@ -100,6 +100,7 @@ mod eventfd {
             Ok(WakerInternal { fd: file })
         }
 
+        #[allow(clippy::unused_io_amount)]
         pub fn wake(&self) -> io::Result<()> {
             let buf: [u8; 8] = 1u64.to_ne_bytes();
             match (&self.fd).write(&buf) {
@@ -120,6 +121,7 @@ mod eventfd {
         }
 
         /// Reset the eventfd object, only need to call this if `wake` fails.
+        #[allow(clippy::unused_io_amount)]
         fn reset(&self) -> io::Result<()> {
             let mut buf: [u8; 8] = 0u64.to_ne_bytes();
             match (&self.fd).read(&mut buf) {

src/sys/wasi/mod.rs

@@ -207,7 +207,7 @@ impl Selector {
 }
 
 /// Token used to a add a timeout subscription, also used in removing it again.
-const TIMEOUT_TOKEN: wasi::Userdata = wasi::Userdata::max_value();
+const TIMEOUT_TOKEN: wasi::Userdata = wasi::Userdata::MAX;
 
 /// Returns a `wasi::Subscription` for `timeout`.
 fn timeout_subscription(timeout: Duration) -> wasi::Subscription {

src/sys/windows/iocp.rs

@@ -96,7 +96,7 @@ impl CompletionPort {
         );
         let mut removed = 0;
         let timeout = duration_millis(timeout);
-        let len = cmp::min(list.len(), <u32>::max_value() as usize) as u32;
+        let len = cmp::min(list.len(), u32::MAX as usize) as u32;
         let ret = unsafe {
             GetQueuedCompletionStatusEx(
                 self.handle.raw(),

src/sys/windows/tcp.rs

@@ -50,7 +50,7 @@ pub(crate) fn listen(socket: &net::TcpListener, backlog: u32) -> io::Result<()>
     use std::convert::TryInto;
     use WinSock::listen;
 
-    let backlog = backlog.try_into().unwrap_or(i32::max_value());
+    let backlog = backlog.try_into().unwrap_or(i32::MAX);
     syscall!(
         listen(socket.as_raw_socket() as _, backlog),
         PartialEq::eq,

tests/tcp.rs

@@ -584,6 +584,7 @@ fn connect_error() {
 }
 
 #[test]
+#[allow(clippy::unused_io_amount)]
 fn write_error() {
     init();