style: address clippy lints (#827)

Cargo.toml

@@ -18,7 +18,7 @@ lazy_static = "1.4.0"
 pin-project-lite = "0.2.7"
 quickcheck = "1"
 rand = "0.8"
-slab = "0.4"
+slab = "0.4.9"
 sync_wrapper = "1"
 tokio = "1.6.2"
 tokio-stream = "0.1.0"

tower-layer/src/layer_fn.rs

@@ -109,7 +109,7 @@ mod tests {
 
         assert_eq!(
             "LayerFn { f: tower_layer::layer_fn::tests::layer_fn_has_useful_debug_impl::{{closure}} }".to_string(),
-            format!("{:?}", layer),
+            format!("{layer:?}"),
         );
     }
 }

tower-layer/src/lib.rs

@@ -105,7 +105,7 @@ pub trait Layer<S> {
     fn layer(&self, inner: S) -> Self::Service;
 }
 
-impl<'a, T, S> Layer<S> for &'a T
+impl<T, S> Layer<S> for &T
 where
     T: ?Sized + Layer<S>,
 {

tower-test/src/mock/mod.rs

@@ -18,7 +18,6 @@ use std::{
     future::Future,
     sync::{Arc, Mutex},
     task::{Context, Poll},
-    u64,
 };
 
 /// Spawn a layer onto a mock service.

tower/examples/tower-balance.rs

@@ -46,13 +46,13 @@ struct Summary {
 async fn main() {
     tracing::subscriber::set_global_default(tracing_subscriber::FmtSubscriber::default()).unwrap();
 
-    println!("REQUESTS={}", REQUESTS);
-    println!("CONCURRENCY={}", CONCURRENCY);
-    println!("ENDPOINT_CAPACITY={}", ENDPOINT_CAPACITY);
+    println!("REQUESTS={REQUESTS}");
+    println!("CONCURRENCY={CONCURRENCY}");
+    println!("ENDPOINT_CAPACITY={ENDPOINT_CAPACITY}");
     print!("MAX_ENDPOINT_LATENCIES=[");
     for max in &MAX_ENDPOINT_LATENCIES {
         let l = max.as_secs() * 1_000 + u64::from(max.subsec_millis());
-        print!("{}ms, ", l);
+        print!("{l}ms, ");
     }
     println!("]");
 
@@ -149,7 +149,7 @@ where
     <D::Service as Service<Req>>::Future: Send,
     <D::Service as load::Load>::Metric: std::fmt::Debug,
 {
-    println!("{}", name);
+    println!("{name}");
 
     let requests = stream::repeat(Req).take(REQUESTS);
     let service = ConcurrencyLimit::new(lb, CONCURRENCY);
@@ -193,7 +193,7 @@ impl Summary {
         }
         for (i, c) in self.count_by_instance.iter().enumerate() {
             let p = *c as f64 / total as f64 * 100.0;
-            println!("  [{:02}] {:>5.01}%", i, p);
+            println!("  [{i:02}] {p:>5.01}%");
         }
 
         println!("  wall {:4}s", self.start.elapsed().as_secs());

tower/src/buffer/layer.rs

@@ -56,7 +56,7 @@ where
 }
 
 impl<Request> fmt::Debug for BufferLayer<Request> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("BufferLayer")
             .field("bound", &self.bound)
             .finish()
@@ -65,10 +65,7 @@ impl<Request> fmt::Debug for BufferLayer<Request> {
 
 impl<Request> Clone for BufferLayer<Request> {
     fn clone(&self) -> Self {
-        Self {
-            bound: self.bound,
-            _p: PhantomData,
-        }
+        *self
     }
 }
 

tower/src/load/peak_ewma.rs

@@ -398,7 +398,7 @@ mod tests {
         assert_eq!(super::nanos(Duration::new(0, 123)), 123.0);
         assert_eq!(super::nanos(Duration::new(1, 23)), 1_000_000_023.0);
         assert_eq!(
-            super::nanos(Duration::new(::std::u64::MAX, 999_999_999)),
+            super::nanos(Duration::new(u64::MAX, 999_999_999)),
             18446744074709553000.0
         );
     }

tower/src/retry/budget/tps_budget.rs

@@ -72,7 +72,7 @@ impl TpsBudget {
         assert!(ttl <= Duration::from_secs(60));
         assert!(retry_percent >= 0.0);
         assert!(retry_percent <= 1000.0);
-        assert!(min_per_sec < ::std::i32::MAX as u32);
+        assert!(min_per_sec < i32::MAX as u32);
 
         let (deposit_amount, withdraw_amount) = if retry_percent == 0.0 {
             // If there is no percent, then you gain nothing from deposits.

tower/src/util/future_service.rs

@@ -186,14 +186,14 @@ mod tests {
         let mut pending_svc = future_service(ready(Ok(DebugService)));
 
         assert_eq!(
-            format!("{:?}", pending_svc),
+            format!("{pending_svc:?}"),
             "FutureService { state: State::Future(<core::future::ready::Ready<core::result::Result<tower::util::future_service::tests::DebugService, core::convert::Infallible>>>) }"
         );
 
         pending_svc.ready().await.unwrap();
 
         assert_eq!(
-            format!("{:?}", pending_svc),
+            format!("{pending_svc:?}"),
             "FutureService { state: State::Service(DebugService) }"
         );
     }

tower/src/util/oneshot.rs

@@ -88,7 +88,7 @@ where
         loop {
             match this.state.as_mut().project() {
                 StateProj::NotReady { svc, req } => {
-                    let _ = ready!(svc.poll_ready(cx))?;
+                    ready!(svc.poll_ready(cx))?;
                     let f = svc.call(req.take().expect("already called"));
                     this.state.set(State::called(f));
                 }

tower/src/util/rng.rs

@@ -132,20 +132,24 @@ mod tests {
 
     quickcheck! {
         fn next_f64(counter: u64) -> TestResult {
-            let mut rng = HasherRng::default();
-            rng.counter = counter;
+            let mut rng = HasherRng {
+                counter,
+                ..HasherRng::default()
+            };
             let n = rng.next_f64();
 
-            TestResult::from_bool(n < 1.0 && n >= 0.0)
+            TestResult::from_bool((0.0..1.0).contains(&n))
         }
 
         fn next_range(counter: u64, range: Range<u64>) -> TestResult {
-            if  range.start >= range.end{
+            if range.start >= range.end{
                 return TestResult::discard();
             }
 
-            let mut rng = HasherRng::default();
-            rng.counter = counter;
+            let mut rng = HasherRng {
+                counter,
+                ..HasherRng::default()
+            };
 
             let n = rng.next_range(range.clone());
 
@@ -153,12 +157,14 @@ mod tests {
         }
 
         fn sample_floyd2(counter: u64, length: u64) -> TestResult {
-            if length < 2 || length > 256 {
+            if !(2..=256).contains(&length) {
                 return TestResult::discard();
             }
 
-            let mut rng = HasherRng::default();
-            rng.counter = counter;
+            let mut rng = HasherRng {
+                counter,
+                ..HasherRng::default()
+            };
 
             let [a, b] = super::sample_floyd2(&mut rng, length);
 

tower/tests/balance/main.rs

@@ -45,7 +45,7 @@ fn stress() {
     for _ in 0..100_000 {
         for _ in 0..(rand::random::<u8>() % 8) {
             if !services.is_empty() && rand::random() {
-                if nready == 0 || rand::random::<u8>() > u8::max_value() / 4 {
+                if nready == 0 || rand::random::<u8>() > u8::MAX / 4 {
                     // ready a service
                     // TODO: sometimes ready a removed service?
                     for (_, (handle, ready)) in &mut services {
@@ -114,7 +114,8 @@ fn stress() {
                 } else {
                     // remove
                     while !services.is_empty() {
-                        let k = rand::random::<usize>() % (services.iter().last().unwrap().0 + 1);
+                        let k =
+                            rand::random::<usize>() % (services.iter().next_back().unwrap().0 + 1);
                         if services.contains(k) {
                             let (handle, ready) = services.remove(k);
                             if ready {
@@ -129,7 +130,7 @@ fn stress() {
             } else {
                 // fail a service
                 while !services.is_empty() {
-                    let k = rand::random::<usize>() % (services.iter().last().unwrap().0 + 1);
+                    let k = rand::random::<usize>() % (services.iter().next_back().unwrap().0 + 1);
                     if services.contains(k) {
                         let (mut handle, ready) = services.remove(k);
                         if ready {