6 files changed, 17 insertions, 17 deletions
diff --git a/library/std/src/sync/mod.rs b/library/std/src/sync/mod.rs
index ee35598bab5..87d01daeafc 100644
--- a/library/std/src/sync/mod.rs
+++ b/library/std/src/sync/mod.rs
@@ -19,7 +19,7 @@
 //!         B = 4;
 //!         A = A + B;
 //!         C = B;
-//!         println!("{} {} {}", A, B, C);
+//!         println!("{A} {B} {C}");
 //!         C = A;
 //!     }
 //! }
diff --git a/library/std/src/sync/mpsc/mod.rs b/library/std/src/sync/mpsc/mod.rs
index 2e54321e127..e85a8723965 100644
--- a/library/std/src/sync/mpsc/mod.rs
+++ b/library/std/src/sync/mpsc/mod.rs
@@ -129,7 +129,7 @@
 //!
 //! // Unbounded receiver waiting for all senders to complete.
 //! while let Ok(msg) = rx.recv() {
-//!     println!("{}", msg);
+//!     println!("{msg}");
 //! }
 //!
 //! println!("completed");
@@ -376,7 +376,7 @@ impl<T> !Sync for Receiver<T> {}
 /// });
 ///
 /// for x in recv.iter() {
-///     println!("Got: {}", x);
+///     println!("Got: {x}");
 /// }
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -419,7 +419,7 @@ pub struct Iter<'a, T: 'a> {
 /// thread::sleep(Duration::from_secs(2)); // block for two seconds
 ///
 /// for x in receiver.try_iter() {
-///     println!("Got: {}", x);
+///     println!("Got: {x}");
 /// }
 /// ```
 #[stable(feature = "receiver_try_iter", since = "1.15.0")]
@@ -453,7 +453,7 @@ pub struct TryIter<'a, T: 'a> {
 /// });
 ///
 /// for x in recv.into_iter() {
-///     println!("Got: {}", x);
+///     println!("Got: {x}");
 /// }
 /// ```
 #[stable(feature = "receiver_into_iter", since = "1.1.0")]
@@ -544,16 +544,16 @@ impl<T> !Sync for Sender<T> {}
 /// let mut msg;
 ///
 /// msg = receiver.recv().unwrap();
-/// println!("message {} received", msg);
+/// println!("message {msg} received");
 ///
 /// // "Thread unblocked!" will be printed now
 ///
 /// msg = receiver.recv().unwrap();
-/// println!("message {} received", msg);
+/// println!("message {msg} received");
 ///
 /// msg = receiver.recv().unwrap();
 ///
-/// println!("message {} received", msg);
+/// println!("message {msg} received");
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct SyncSender<T> {
@@ -996,14 +996,14 @@ impl<T> SyncSender<T> {
     ///
     /// let mut msg;
     /// msg = receiver.recv().unwrap();
-    /// println!("message {} received", msg);
+    /// println!("message {msg} received");
     ///
     /// msg = receiver.recv().unwrap();
-    /// println!("message {} received", msg);
+    /// println!("message {msg} received");
     ///
     /// // Third message may have never been sent
     /// match receiver.try_recv() {
-    ///     Ok(msg) => println!("message {} received", msg),
+    ///     Ok(msg) => println!("message {msg} received"),
     ///     Err(_) => println!("the third message was never sent"),
     /// }
     /// ```
diff --git a/library/std/src/sync/mpsc/shared.rs b/library/std/src/sync/mpsc/shared.rs
index 8487a5f8b50..56162655544 100644
--- a/library/std/src/sync/mpsc/shared.rs
+++ b/library/std/src/sync/mpsc/shared.rs
@@ -369,7 +369,7 @@ impl<T> Packet<T> {
         match self.channels.fetch_sub(1, Ordering::SeqCst) {
             1 => {}
             n if n > 1 => return,
-            n => panic!("bad number of channels left {}", n),
+            n => panic!("bad number of channels left {n}"),
         }
 
         match self.cnt.swap(DISCONNECTED, Ordering::SeqCst) {
diff --git a/library/std/src/sync/mutex/tests.rs b/library/std/src/sync/mutex/tests.rs
index a1b5aeddcb6..93900566f11 100644
--- a/library/std/src/sync/mutex/tests.rs
+++ b/library/std/src/sync/mutex/tests.rs
@@ -94,7 +94,7 @@ fn test_into_inner_poison() {
     assert!(m.is_poisoned());
     match Arc::try_unwrap(m).unwrap().into_inner() {
         Err(e) => assert_eq!(e.into_inner(), NonCopy(10)),
-        Ok(x) => panic!("into_inner of poisoned Mutex is Ok: {:?}", x),
+        Ok(x) => panic!("into_inner of poisoned Mutex is Ok: {x:?}"),
     }
 }
 
@@ -118,7 +118,7 @@ fn test_get_mut_poison() {
     assert!(m.is_poisoned());
     match Arc::try_unwrap(m).unwrap().get_mut() {
         Err(e) => assert_eq!(*e.into_inner(), NonCopy(10)),
-        Ok(x) => panic!("get_mut of poisoned Mutex is Ok: {:?}", x),
+        Ok(x) => panic!("get_mut of poisoned Mutex is Ok: {x:?}"),
     }
 }
 
diff --git a/library/std/src/sync/poison.rs b/library/std/src/sync/poison.rs
index fa950331e64..07a90da449c 100644
--- a/library/std/src/sync/poison.rs
+++ b/library/std/src/sync/poison.rs
@@ -73,7 +73,7 @@ pub struct Guard {
 ///     Ok(_) => unreachable!(),
 ///     Err(p_err) => {
 ///         let data = p_err.get_ref();
-///         println!("recovered: {}", data);
+///         println!("recovered: {data}");
 ///     }
 /// };
 /// ```
diff --git a/library/std/src/sync/rwlock/tests.rs b/library/std/src/sync/rwlock/tests.rs
index e9b74fb3ecc..53aa2b1e38a 100644
--- a/library/std/src/sync/rwlock/tests.rs
+++ b/library/std/src/sync/rwlock/tests.rs
@@ -218,7 +218,7 @@ fn test_into_inner_poison() {
     assert!(m.is_poisoned());
     match Arc::try_unwrap(m).unwrap().into_inner() {
         Err(e) => assert_eq!(e.into_inner(), NonCopy(10)),
-        Ok(x) => panic!("into_inner of poisoned RwLock is Ok: {:?}", x),
+        Ok(x) => panic!("into_inner of poisoned RwLock is Ok: {x:?}"),
     }
 }
 
@@ -242,6 +242,6 @@ fn test_get_mut_poison() {
     assert!(m.is_poisoned());
     match Arc::try_unwrap(m).unwrap().get_mut() {
         Err(e) => assert_eq!(*e.into_inner(), NonCopy(10)),
-        Ok(x) => panic!("get_mut of poisoned RwLock is Ok: {:?}", x),
+        Ok(x) => panic!("get_mut of poisoned RwLock is Ok: {x:?}"),
     }
 }