silence warnings reported by newer rust versions

Author: Keruspe

examples/a-chat/server.rs

@@ -96,6 +96,7 @@ async fn connection_writer_loop(
                 None => break,
             },
             void = shutdown.next().fuse() => match void {
+                #[allow(unreachable_patterns)]
                 Some(void) => match void {},
                 None => break,
             }

src/future/future/mod.rs

@@ -27,6 +27,7 @@ pub use core::future::Future as Future;
 
     [`Future`]: ../future/trait.Future.html
 "#]
+#[cfg(any(feature = "unstable", feature = "docs"))]
 pub trait FutureExt: Future {
     /// Returns a Future that delays execution for a specified time.
     ///
@@ -284,5 +285,6 @@ pub trait FutureExt: Future {
     }
 }
 
+#[cfg(any(feature = "unstable", feature = "docs"))]
 impl<T: Future + ?Sized> FutureExt for T {}
 

src/io/buf_writer.rs

@@ -114,7 +114,7 @@ pin_project! {
 /// # Ok(()) }) }
 ///```
 #[derive(Debug)]
-pub struct IntoInnerError<W>(W, crate::io::Error);
+pub struct IntoInnerError<W>(W, #[allow(dead_code)] crate::io::Error);
 
 impl<W: Write> BufWriter<W> {
     /// Creates a new `BufWriter` with a default buffer capacity. The default is currently 8 KB,

src/io/read/bytes.rs

@@ -32,7 +32,7 @@ impl<T: Read + Unpin> Stream for Bytes<T> {
     }
 }
 
-#[cfg(all(test, default))]
+#[cfg(all(test, feature = "default"))]
 mod tests {
     use crate::io;
     use crate::prelude::*;

src/io/read/chain.rs

@@ -165,7 +165,7 @@ impl<T: BufRead, U: BufRead> BufRead for Chain<T, U> {
     }
 }
 
-#[cfg(all(test, default))]
+#[cfg(all(test, feature = "default"))]
 mod tests {
     use crate::io;
     use crate::prelude::*;

src/lib.rs

@@ -284,8 +284,6 @@
 #![doc(test(attr(allow(unused_extern_crates, unused_variables))))]
 #![doc(html_logo_url = "https://async.rs/images/logo--hero.svg")]
 
-extern crate alloc;
-
 #[macro_use]
 mod utils;
 

src/utils.rs

@@ -1,5 +1,3 @@
-use alloc::string::String;
-
 /// Calls a function and aborts if it panics.
 ///
 /// This is useful in unsafe code where we can't recover from panics.
@@ -55,8 +53,9 @@ pub fn random(n: u32) -> u32 {
 }
 
 /// Add additional context to errors
+#[cfg(any(feature = "unstable", feature = "default"))]
 pub(crate) trait Context {
-    fn context(self, message: impl Fn() -> String) -> Self;
+    fn context(self, message: impl Fn() -> alloc::string::String) -> Self;
 }
 
 #[cfg(all(