chore: deny warnings for doc tests (#1539)

tokio/src/executor.rs

@@ -71,7 +71,7 @@ pub struct Spawn(());
 /// ```
 /// use tokio::net::TcpListener;
 ///
-/// # async fn process<T>(t: T) {}
+/// # async fn process<T>(_t: T) {}
 /// # async fn dox() -> Result<(), Box<dyn std::error::Error>> {
 /// let mut listener = TcpListener::bind("127.0.0.1:8080").await?;
 ///

tokio/src/lib.rs

@@ -6,7 +6,10 @@
     unreachable_pub
 )]
 #![deny(intra_doc_link_resolution_failure)]
-#![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]
+#![doc(test(
+    no_crate_inject,
+    attr(deny(warnings, rust_2018_idioms), allow(dead_code, unused_variables))
+))]
 
 //! A runtime for writing reliable, asynchronous, and slim applications.
 //!

tokio/src/runtime/current_thread/mod.rs

@@ -25,14 +25,13 @@
 //!
 //! ```
 //! use tokio::runtime::current_thread::Runtime;
-//! use tokio::prelude::*;
 //! use std::thread;
 //!
-//! let mut runtime = Runtime::new().unwrap();
+//! let runtime = Runtime::new().unwrap();
 //! let handle = runtime.handle();
 //!
 //! thread::spawn(move || {
-//!     handle.spawn(async {
+//!     let _ = handle.spawn(async {
 //!         println!("hello world");
 //!     });
 //! }).join().unwrap();
@@ -45,9 +44,8 @@
 //!
 //! ```
 //! use tokio::runtime::current_thread::Runtime;
-//! use tokio::prelude::*;
 //!
-//! let mut runtime = Runtime::new().unwrap();
+//! let runtime = Runtime::new().unwrap();
 //!
 //! // Use the runtime...
 //! // runtime.block_on(f); // where f is a future

tokio/src/runtime/mod.rs

@@ -86,7 +86,7 @@
 //!
 //! fn main() -> Result<(), Box<dyn std::error::Error>> {
 //!     // Create the runtime
-//!     let mut rt = Runtime::new()?;
+//!     let rt = Runtime::new()?;
 //!
 //!     // Spawn the root task
 //!     rt.block_on(async {

tokio/src/runtime/threadpool/builder.rs

@@ -35,7 +35,7 @@ use std::any::Any;
 ///
 /// fn main() {
 ///     // build Runtime
-///     let mut runtime = Builder::new()
+///     let runtime = Builder::new()
 ///         .blocking_threads(4)
 ///         .clock(Clock::system())
 ///         .core_threads(4)
@@ -99,7 +99,7 @@ impl Builder {
     /// # use tokio::runtime;
     ///
     /// # pub fn main() {
-    /// let mut rt = runtime::Builder::new()
+    /// let rt = runtime::Builder::new()
     ///     .panic_handler(|err| std::panic::resume_unwind(err))
     ///     .build()
     ///     .unwrap();
@@ -127,7 +127,7 @@ impl Builder {
     /// # use tokio::runtime;
     ///
     /// # pub fn main() {
-    /// let mut rt = runtime::Builder::new()
+    /// let rt = runtime::Builder::new()
     ///     .core_threads(4)
     ///     .build()
     ///     .unwrap();
@@ -157,7 +157,7 @@ impl Builder {
     /// # use tokio::runtime;
     ///
     /// # pub fn main() {
-    /// let mut rt = runtime::Builder::new()
+    /// let rt = runtime::Builder::new()
     ///     .blocking_threads(200)
     ///     .build();
     /// # }
@@ -186,7 +186,7 @@ impl Builder {
     /// use std::time::Duration;
     ///
     /// # pub fn main() {
-    /// let mut rt = runtime::Builder::new()
+    /// let rt = runtime::Builder::new()
     ///     .keep_alive(Some(Duration::from_secs(30)))
     ///     .build();
     /// # }
@@ -210,7 +210,7 @@ impl Builder {
     /// # use tokio::runtime;
     ///
     /// # pub fn main() {
-    /// let mut rt = runtime::Builder::new()
+    /// let rt = runtime::Builder::new()
     ///     .name_prefix("my-pool-")
     ///     .build();
     /// # }
@@ -234,7 +234,7 @@ impl Builder {
     /// # use tokio::runtime;
     ///
     /// # pub fn main() {
-    /// let mut rt = runtime::Builder::new()
+    /// let rt = runtime::Builder::new()
     ///     .stack_size(32 * 1024)
     ///     .build();
     /// # }

tokio/src/runtime/threadpool/mod.rs

@@ -75,7 +75,6 @@ impl Runtime {
     ///
     /// ```
     /// use tokio::runtime::Runtime;
-    /// use tokio::prelude::*;
     ///
     /// let rt = Runtime::new()
     ///     .unwrap();
@@ -198,7 +197,6 @@ impl Runtime {
     ///
     /// ```
     /// use tokio::runtime::Runtime;
-    /// use tokio::prelude::*;
     ///
     /// let rt = Runtime::new()
     ///     .unwrap();
@@ -239,7 +237,6 @@ impl Runtime {
     ///
     /// ```
     /// use tokio::runtime::Runtime;
-    /// use tokio::prelude::*;
     ///
     /// let rt = Runtime::new()
     ///     .unwrap();

tokio/src/runtime/threadpool/task_executor.rs

@@ -33,7 +33,7 @@ impl TaskExecutor {
     ///
     /// # fn dox() {
     /// // Create the runtime
-    /// let mut rt = Runtime::new().unwrap();
+    /// let rt = Runtime::new().unwrap();
     /// let executor = rt.executor();
     ///
     /// // Spawn a future onto the runtime

tokio/src/timer.rs

@@ -30,10 +30,9 @@
 //! Wait 100ms and print "Hello World!"
 //!
 //! ```
-//! use tokio::prelude::*;
 //! use tokio::timer::delay;
 //!
-//! use std::time::{Duration, Instant};
+//! use std::time::Duration;
 //!
 //!
 //! #[tokio::main]