From 1197d3b5c9c59c4b362977743957da042f233bc9 Mon Sep 17 00:00:00 2001
From: Yuri Astrakhan <YuriAstrakhan@gmail.com>
Date: Sat, 5 Feb 2022 21:36:35 -0500
Subject: [PATCH] Use v1.58 captured ident formatting in examples

Per https://github.com/rust-lang/book/issues/3047, use captured identifiers instead of the positional ones for some examples, e.g.

```diff
-  println!("Worker {} got a job; executing.", id);
+  println!("Worker {id} got a job; executing.");
```
---
 .../ch02-guessing-game-tutorial/listing-02-01/src/main.rs   | 2 +-
 .../ch02-guessing-game-tutorial/listing-02-02/src/main.rs   | 2 +-
 .../listing-03-03/src/main.rs                               | 2 +-
 .../src/main.rs                                             | 2 +-
 .../no-listing-34-for-range/src/main.rs                     | 2 +-
 .../ch04-understanding-ownership/listing-04-05/src/main.rs  | 2 +-
 .../no-listing-05-clone/src/main.rs                         | 2 +-
 .../no-listing-06-copy/src/main.rs                          | 2 +-
 .../no-listing-07-reference/src/main.rs                     | 2 +-
 .../no-listing-08-reference-with-annotations/src/main.rs    | 2 +-
 .../no-listing-09-variable-in-pattern/src/main.rs           | 2 +-
 .../no-listing-13-count-and-announce-match/src/main.rs      | 2 +-
 .../src/main.rs                                             | 2 +-
 .../no-listing-05-greeter/src/lib.rs                        | 2 +-
 listings/ch13-functional-features/listing-13-04/src/main.rs | 6 +++---
 listings/ch15-smart-pointers/listing-15-11/src/main.rs      | 2 +-
 listings/ch15-smart-pointers/listing-15-12/src/main.rs      | 2 +-
 listings/ch15-smart-pointers/listing-15-13/src/main.rs      | 2 +-
 .../ch16-fearless-concurrency/listing-16-01/src/main.rs     | 4 ++--
 .../ch16-fearless-concurrency/listing-16-02/src/main.rs     | 4 ++--
 .../no-listing-01-join-too-early/src/main.rs                | 4 ++--
 .../ch18-patterns-and-matching/listing-18-01/src/main.rs    | 2 +-
 .../ch18-patterns-and-matching/listing-18-11/src/main.rs    | 6 +++---
 .../ch18-patterns-and-matching/listing-18-19/src/main.rs    | 2 +-
 .../ch18-patterns-and-matching/listing-18-24/src/main.rs    | 2 +-
 .../ch18-patterns-and-matching/listing-18-27/src/main.rs    | 6 +++---
 listings/ch20-web-server/listing-20-20/src/lib.rs           | 2 +-
 listings/ch20-web-server/listing-20-21/src/lib.rs           | 2 +-
 listings/ch20-web-server/listing-20-22/src/lib.rs           | 2 +-
 listings/ch20-web-server/listing-20-23/src/lib.rs           | 4 ++--
 listings/ch20-web-server/listing-20-24/src/lib.rs           | 4 ++--
 listings/ch20-web-server/listing-20-25/src/lib.rs           | 4 ++--
 .../no-listing-04-update-worker-definition/src/lib.rs       | 2 +-
 .../ch20-web-server/no-listing-05-fix-worker-new/src/lib.rs | 2 +-
 .../no-listing-06-fix-threadpool-drop/src/lib.rs            | 2 +-
 .../no-listing-07-define-message-enum/src/lib.rs            | 2 +-
 .../ch20-web-server/no-listing-08-final-code/src/lib.rs     | 4 ++--
 redirects/loops.md                                          | 6 +++---
 38 files changed, 53 insertions(+), 53 deletions(-)

diff --git a/listings/ch02-guessing-game-tutorial/listing-02-01/src/main.rs b/listings/ch02-guessing-game-tutorial/listing-02-01/src/main.rs
index b822b89ff3..d44e290d70 100644
--- a/listings/ch02-guessing-game-tutorial/listing-02-01/src/main.rs
+++ b/listings/ch02-guessing-game-tutorial/listing-02-01/src/main.rs
@@ -25,7 +25,7 @@ fn main() {
     // ANCHOR_END: expect
 
     // ANCHOR: print_guess
-    println!("You guessed: {}", guess);
+    println!("You guessed: {guess}");
     // ANCHOR_END: print_guess
 }
 // ANCHOR: all
diff --git a/listings/ch02-guessing-game-tutorial/listing-02-02/src/main.rs b/listings/ch02-guessing-game-tutorial/listing-02-02/src/main.rs
index 60fb2a8e5f..b35ed0f2f5 100644
--- a/listings/ch02-guessing-game-tutorial/listing-02-02/src/main.rs
+++ b/listings/ch02-guessing-game-tutorial/listing-02-02/src/main.rs
@@ -11,5 +11,5 @@ fn main() {
         .read_line(&mut guess)
         .expect("Failed to read line");
 
-    println!("You guessed: {}", guess);
+    println!("You guessed: {guess}");
 }
diff --git a/listings/ch03-common-programming-concepts/listing-03-03/src/main.rs b/listings/ch03-common-programming-concepts/listing-03-03/src/main.rs
index 651ed68c8e..ca070c759d 100644
--- a/listings/ch03-common-programming-concepts/listing-03-03/src/main.rs
+++ b/listings/ch03-common-programming-concepts/listing-03-03/src/main.rs
@@ -2,7 +2,7 @@ fn main() {
     let mut number = 3;
 
     while number != 0 {
-        println!("{}!", number);
+        println!("{number}!");
 
         number -= 1;
     }
diff --git a/listings/ch03-common-programming-concepts/no-listing-18-functions-with-multiple-parameters/src/main.rs b/listings/ch03-common-programming-concepts/no-listing-18-functions-with-multiple-parameters/src/main.rs
index 543c2ea45f..b070ccb23c 100644
--- a/listings/ch03-common-programming-concepts/no-listing-18-functions-with-multiple-parameters/src/main.rs
+++ b/listings/ch03-common-programming-concepts/no-listing-18-functions-with-multiple-parameters/src/main.rs
@@ -3,5 +3,5 @@ fn main() {
 }
 
 fn print_labeled_measurement(value: i32, unit_label: char) {
-    println!("The measurement is: {}{}", value, unit_label);
+    println!("The measurement is: {value}{unit_label}");
 }
diff --git a/listings/ch03-common-programming-concepts/no-listing-34-for-range/src/main.rs b/listings/ch03-common-programming-concepts/no-listing-34-for-range/src/main.rs
index e7286a84e4..df5b305bca 100644
--- a/listings/ch03-common-programming-concepts/no-listing-34-for-range/src/main.rs
+++ b/listings/ch03-common-programming-concepts/no-listing-34-for-range/src/main.rs
@@ -1,6 +1,6 @@
 fn main() {
     for number in (1..4).rev() {
-        println!("{}!", number);
+        println!("{number}!");
     }
     println!("LIFTOFF!!!");
 }
diff --git a/listings/ch04-understanding-ownership/listing-04-05/src/main.rs b/listings/ch04-understanding-ownership/listing-04-05/src/main.rs
index 22aee1419e..2782483a77 100644
--- a/listings/ch04-understanding-ownership/listing-04-05/src/main.rs
+++ b/listings/ch04-understanding-ownership/listing-04-05/src/main.rs
@@ -3,7 +3,7 @@ fn main() {
 
     let (s2, len) = calculate_length(s1);
 
-    println!("The length of '{}' is {}.", s2, len);
+    println!("The length of '{s2}' is {len}.");
 }
 
 fn calculate_length(s: String) -> (String, usize) {
diff --git a/listings/ch04-understanding-ownership/no-listing-05-clone/src/main.rs b/listings/ch04-understanding-ownership/no-listing-05-clone/src/main.rs
index 4e61cc1a16..0b65e5f611 100644
--- a/listings/ch04-understanding-ownership/no-listing-05-clone/src/main.rs
+++ b/listings/ch04-understanding-ownership/no-listing-05-clone/src/main.rs
@@ -3,6 +3,6 @@ fn main() {
     let s1 = String::from("hello");
     let s2 = s1.clone();
 
-    println!("s1 = {}, s2 = {}", s1, s2);
+    println!("s1 = {s1}, s2 = {s2}");
     // ANCHOR_END: here
 }
diff --git a/listings/ch04-understanding-ownership/no-listing-06-copy/src/main.rs b/listings/ch04-understanding-ownership/no-listing-06-copy/src/main.rs
index 63a1fae248..b6fd2445d0 100644
--- a/listings/ch04-understanding-ownership/no-listing-06-copy/src/main.rs
+++ b/listings/ch04-understanding-ownership/no-listing-06-copy/src/main.rs
@@ -3,6 +3,6 @@ fn main() {
     let x = 5;
     let y = x;
 
-    println!("x = {}, y = {}", x, y);
+    println!("x = {x}, y = {y}");
     // ANCHOR_END: here
 }
diff --git a/listings/ch04-understanding-ownership/no-listing-07-reference/src/main.rs b/listings/ch04-understanding-ownership/no-listing-07-reference/src/main.rs
index fd32a5fc95..6f6d5fb239 100644
--- a/listings/ch04-understanding-ownership/no-listing-07-reference/src/main.rs
+++ b/listings/ch04-understanding-ownership/no-listing-07-reference/src/main.rs
@@ -6,7 +6,7 @@ fn main() {
     let len = calculate_length(&s1);
     // ANCHOR_END: here
 
-    println!("The length of '{}' is {}.", s1, len);
+    println!("The length of '{s1}' is {len}.");
 }
 
 fn calculate_length(s: &String) -> usize {
diff --git a/listings/ch04-understanding-ownership/no-listing-08-reference-with-annotations/src/main.rs b/listings/ch04-understanding-ownership/no-listing-08-reference-with-annotations/src/main.rs
index 6e40b8c300..00eafe0894 100644
--- a/listings/ch04-understanding-ownership/no-listing-08-reference-with-annotations/src/main.rs
+++ b/listings/ch04-understanding-ownership/no-listing-08-reference-with-annotations/src/main.rs
@@ -3,7 +3,7 @@ fn main() {
 
     let len = calculate_length(&s1);
 
-    println!("The length of '{}' is {}.", s1, len);
+    println!("The length of '{s1}' is {len}.");
 }
 
 // ANCHOR: here
diff --git a/listings/ch06-enums-and-pattern-matching/no-listing-09-variable-in-pattern/src/main.rs b/listings/ch06-enums-and-pattern-matching/no-listing-09-variable-in-pattern/src/main.rs
index a4d500c11c..298215d405 100644
--- a/listings/ch06-enums-and-pattern-matching/no-listing-09-variable-in-pattern/src/main.rs
+++ b/listings/ch06-enums-and-pattern-matching/no-listing-09-variable-in-pattern/src/main.rs
@@ -19,7 +19,7 @@ fn value_in_cents(coin: Coin) -> u8 {
         Coin::Nickel => 5,
         Coin::Dime => 10,
         Coin::Quarter(state) => {
-            println!("State quarter from {:?}!", state);
+            println!("State quarter from {state:?}!");
             25
         }
     }
diff --git a/listings/ch06-enums-and-pattern-matching/no-listing-13-count-and-announce-match/src/main.rs b/listings/ch06-enums-and-pattern-matching/no-listing-13-count-and-announce-match/src/main.rs
index 12c4c0fec1..d0d7d80271 100644
--- a/listings/ch06-enums-and-pattern-matching/no-listing-13-count-and-announce-match/src/main.rs
+++ b/listings/ch06-enums-and-pattern-matching/no-listing-13-count-and-announce-match/src/main.rs
@@ -17,7 +17,7 @@ fn main() {
     // ANCHOR: here
     let mut count = 0;
     match coin {
-        Coin::Quarter(state) => println!("State quarter from {:?}!", state),
+        Coin::Quarter(state) => println!("State quarter from {state:?}!"),
         _ => count += 1,
     }
     // ANCHOR_END: here
diff --git a/listings/ch06-enums-and-pattern-matching/no-listing-14-count-and-announce-if-let-else/src/main.rs b/listings/ch06-enums-and-pattern-matching/no-listing-14-count-and-announce-if-let-else/src/main.rs
index ba7eda27b4..3bb3630350 100644
--- a/listings/ch06-enums-and-pattern-matching/no-listing-14-count-and-announce-if-let-else/src/main.rs
+++ b/listings/ch06-enums-and-pattern-matching/no-listing-14-count-and-announce-if-let-else/src/main.rs
@@ -17,7 +17,7 @@ fn main() {
     // ANCHOR: here
     let mut count = 0;
     if let Coin::Quarter(state) = coin {
-        println!("State quarter from {:?}!", state);
+        println!("State quarter from {state:?}!");
     } else {
         count += 1;
     }
diff --git a/listings/ch11-writing-automated-tests/no-listing-05-greeter/src/lib.rs b/listings/ch11-writing-automated-tests/no-listing-05-greeter/src/lib.rs
index 3ba3d8819e..433cf148ea 100644
--- a/listings/ch11-writing-automated-tests/no-listing-05-greeter/src/lib.rs
+++ b/listings/ch11-writing-automated-tests/no-listing-05-greeter/src/lib.rs
@@ -1,5 +1,5 @@
 pub fn greeting(name: &str) -> String {
-    format!("Hello {}!", name)
+    format!("Hello {name}!")
 }
 
 #[cfg(test)]
diff --git a/listings/ch13-functional-features/listing-13-04/src/main.rs b/listings/ch13-functional-features/listing-13-04/src/main.rs
index fabe0fb01d..b0772a3c54 100644
--- a/listings/ch13-functional-features/listing-13-04/src/main.rs
+++ b/listings/ch13-functional-features/listing-13-04/src/main.rs
@@ -12,13 +12,13 @@ fn generate_workout(intensity: u32, random_number: u32) {
     let expensive_result = simulated_expensive_calculation(intensity);
 
     if intensity < 25 {
-        println!("Today, do {} pushups!", expensive_result);
-        println!("Next, do {} situps!", expensive_result);
+        println!("Today, do {expensive_result} pushups!");
+        println!("Next, do {expensive_result} situps!");
     } else {
         if random_number == 3 {
             println!("Take a break today! Remember to stay hydrated!");
         } else {
-            println!("Today, run for {} minutes!", expensive_result);
+            println!("Today, run for {expensive_result} minutes!");
         }
     }
 }
diff --git a/listings/ch15-smart-pointers/listing-15-11/src/main.rs b/listings/ch15-smart-pointers/listing-15-11/src/main.rs
index b73ad89c25..77a88c91f5 100644
--- a/listings/ch15-smart-pointers/listing-15-11/src/main.rs
+++ b/listings/ch15-smart-pointers/listing-15-11/src/main.rs
@@ -1,6 +1,6 @@
 // ANCHOR: here
 fn hello(name: &str) {
-    println!("Hello, {}!", name);
+    println!("Hello, {name}!");
 }
 // ANCHOR_END: here
 
diff --git a/listings/ch15-smart-pointers/listing-15-12/src/main.rs b/listings/ch15-smart-pointers/listing-15-12/src/main.rs
index 6a3e143cc3..8cd3893cb2 100644
--- a/listings/ch15-smart-pointers/listing-15-12/src/main.rs
+++ b/listings/ch15-smart-pointers/listing-15-12/src/main.rs
@@ -17,7 +17,7 @@ impl<T> MyBox<T> {
 }
 
 fn hello(name: &str) {
-    println!("Hello, {}!", name);
+    println!("Hello, {name}!");
 }
 
 // ANCHOR: here
diff --git a/listings/ch15-smart-pointers/listing-15-13/src/main.rs b/listings/ch15-smart-pointers/listing-15-13/src/main.rs
index ef5361c120..9debe2a31f 100644
--- a/listings/ch15-smart-pointers/listing-15-13/src/main.rs
+++ b/listings/ch15-smart-pointers/listing-15-13/src/main.rs
@@ -17,7 +17,7 @@ impl<T> MyBox<T> {
 }
 
 fn hello(name: &str) {
-    println!("Hello, {}!", name);
+    println!("Hello, {name}!");
 }
 
 // ANCHOR: here
diff --git a/listings/ch16-fearless-concurrency/listing-16-01/src/main.rs b/listings/ch16-fearless-concurrency/listing-16-01/src/main.rs
index 6305a98e3d..ea10ba282a 100644
--- a/listings/ch16-fearless-concurrency/listing-16-01/src/main.rs
+++ b/listings/ch16-fearless-concurrency/listing-16-01/src/main.rs
@@ -4,13 +4,13 @@ use std::time::Duration;
 fn main() {
     thread::spawn(|| {
         for i in 1..10 {
-            println!("hi number {} from the spawned thread!", i);
+            println!("hi number {i} from the spawned thread!");
             thread::sleep(Duration::from_millis(1));
         }
     });
 
     for i in 1..5 {
-        println!("hi number {} from the main thread!", i);
+        println!("hi number {i} from the main thread!");
         thread::sleep(Duration::from_millis(1));
     }
 }
diff --git a/listings/ch16-fearless-concurrency/listing-16-02/src/main.rs b/listings/ch16-fearless-concurrency/listing-16-02/src/main.rs
index e37607f1d6..33bf53f400 100644
--- a/listings/ch16-fearless-concurrency/listing-16-02/src/main.rs
+++ b/listings/ch16-fearless-concurrency/listing-16-02/src/main.rs
@@ -4,13 +4,13 @@ use std::time::Duration;
 fn main() {
     let handle = thread::spawn(|| {
         for i in 1..10 {
-            println!("hi number {} from the spawned thread!", i);
+            println!("hi number {i} from the spawned thread!");
             thread::sleep(Duration::from_millis(1));
         }
     });
 
     for i in 1..5 {
-        println!("hi number {} from the main thread!", i);
+        println!("hi number {i} from the main thread!");
         thread::sleep(Duration::from_millis(1));
     }
 
diff --git a/listings/ch16-fearless-concurrency/no-listing-01-join-too-early/src/main.rs b/listings/ch16-fearless-concurrency/no-listing-01-join-too-early/src/main.rs
index 6205e57d33..7023a90f64 100644
--- a/listings/ch16-fearless-concurrency/no-listing-01-join-too-early/src/main.rs
+++ b/listings/ch16-fearless-concurrency/no-listing-01-join-too-early/src/main.rs
@@ -4,7 +4,7 @@ use std::time::Duration;
 fn main() {
     let handle = thread::spawn(|| {
         for i in 1..10 {
-            println!("hi number {} from the spawned thread!", i);
+            println!("hi number {i} from the spawned thread!");
             thread::sleep(Duration::from_millis(1));
         }
     });
@@ -12,7 +12,7 @@ fn main() {
     handle.join().unwrap();
 
     for i in 1..5 {
-        println!("hi number {} from the main thread!", i);
+        println!("hi number {i} from the main thread!");
         thread::sleep(Duration::from_millis(1));
     }
 }
diff --git a/listings/ch18-patterns-and-matching/listing-18-01/src/main.rs b/listings/ch18-patterns-and-matching/listing-18-01/src/main.rs
index d28c369f56..fc87768fb3 100644
--- a/listings/ch18-patterns-and-matching/listing-18-01/src/main.rs
+++ b/listings/ch18-patterns-and-matching/listing-18-01/src/main.rs
@@ -4,7 +4,7 @@ fn main() {
     let age: Result<u8, _> = "34".parse();
 
     if let Some(color) = favorite_color {
-        println!("Using your favorite color, {}, as the background", color);
+        println!("Using your favorite color, {color}, as the background");
     } else if is_tuesday {
         println!("Tuesday is green day!");
     } else if let Ok(age) = age {
diff --git a/listings/ch18-patterns-and-matching/listing-18-11/src/main.rs b/listings/ch18-patterns-and-matching/listing-18-11/src/main.rs
index 25eaa79ff8..c05258c99d 100644
--- a/listings/ch18-patterns-and-matching/listing-18-11/src/main.rs
+++ b/listings/ch18-patterns-and-matching/listing-18-11/src/main.rs
@@ -5,10 +5,10 @@ fn main() {
 
     match x {
         Some(50) => println!("Got 50"),
-        Some(y) => println!("Matched, y = {:?}", y),
-        _ => println!("Default case, x = {:?}", x),
+        Some(y) => println!("Matched, y = {y:?}"),
+        _ => println!("Default case, x = {x:?}"),
     }
 
-    println!("at the end: x = {:?}, y = {:?}", x, y);
+    println!("at the end: x = {x:?}, y = {y:?}");
     // ANCHOR_END: here
 }
diff --git a/listings/ch18-patterns-and-matching/listing-18-19/src/main.rs b/listings/ch18-patterns-and-matching/listing-18-19/src/main.rs
index 59b48c94d8..e28dab111c 100644
--- a/listings/ch18-patterns-and-matching/listing-18-19/src/main.rs
+++ b/listings/ch18-patterns-and-matching/listing-18-19/src/main.rs
@@ -4,7 +4,7 @@ fn main() {
 
     match numbers {
         (first, _, third, _, fifth) => {
-            println!("Some numbers: {}, {}, {}", first, third, fifth)
+            println!("Some numbers: {first}, {third}, {fifth}")
         }
     }
     // ANCHOR_END: here
diff --git a/listings/ch18-patterns-and-matching/listing-18-24/src/main.rs b/listings/ch18-patterns-and-matching/listing-18-24/src/main.rs
index f22dbe8edf..3f9aaafc24 100644
--- a/listings/ch18-patterns-and-matching/listing-18-24/src/main.rs
+++ b/listings/ch18-patterns-and-matching/listing-18-24/src/main.rs
@@ -3,7 +3,7 @@ fn main() {
 
     match numbers {
         (first, .., last) => {
-            println!("Some numbers: {}, {}", first, last);
+            println!("Some numbers: {first}, {last}");
         }
     }
 }
diff --git a/listings/ch18-patterns-and-matching/listing-18-27/src/main.rs b/listings/ch18-patterns-and-matching/listing-18-27/src/main.rs
index 348e367233..06fd949964 100644
--- a/listings/ch18-patterns-and-matching/listing-18-27/src/main.rs
+++ b/listings/ch18-patterns-and-matching/listing-18-27/src/main.rs
@@ -4,9 +4,9 @@ fn main() {
 
     match x {
         Some(50) => println!("Got 50"),
-        Some(n) if n == y => println!("Matched, n = {}", n),
-        _ => println!("Default case, x = {:?}", x),
+        Some(n) if n == y => println!("Matched, n = {n}"),
+        _ => println!("Default case, x = {x:?}"),
     }
 
-    println!("at the end: x = {:?}, y = {}", x, y);
+    println!("at the end: x = {x:?}, y = {y}");
 }
diff --git a/listings/ch20-web-server/listing-20-20/src/lib.rs b/listings/ch20-web-server/listing-20-20/src/lib.rs
index 5fdc32e8b0..e31ab53bd4 100644
--- a/listings/ch20-web-server/listing-20-20/src/lib.rs
+++ b/listings/ch20-web-server/listing-20-20/src/lib.rs
@@ -57,7 +57,7 @@ impl Worker {
         let thread = thread::spawn(move || loop {
             let job = receiver.lock().unwrap().recv().unwrap();
 
-            println!("Worker {} got a job; executing.", id);
+            println!("Worker {id} got a job; executing.");
 
             job();
         });
diff --git a/listings/ch20-web-server/listing-20-21/src/lib.rs b/listings/ch20-web-server/listing-20-21/src/lib.rs
index 6bde524885..55647d8539 100644
--- a/listings/ch20-web-server/listing-20-21/src/lib.rs
+++ b/listings/ch20-web-server/listing-20-21/src/lib.rs
@@ -55,7 +55,7 @@ impl Worker {
     fn new(id: usize, receiver: Arc<Mutex<mpsc::Receiver<Job>>>) -> Worker {
         let thread = thread::spawn(move || {
             while let Ok(job) = receiver.lock().unwrap().recv() {
-                println!("Worker {} got a job; executing.", id);
+                println!("Worker {id} got a job; executing.");
 
                 job();
             }
diff --git a/listings/ch20-web-server/listing-20-22/src/lib.rs b/listings/ch20-web-server/listing-20-22/src/lib.rs
index 824257898c..76b7a3fcfd 100644
--- a/listings/ch20-web-server/listing-20-22/src/lib.rs
+++ b/listings/ch20-web-server/listing-20-22/src/lib.rs
@@ -66,7 +66,7 @@ impl Worker {
         let thread = thread::spawn(move || loop {
             let job = receiver.lock().unwrap().recv().unwrap();
 
-            println!("Worker {} got a job; executing.", id);
+            println!("Worker {id} got a job; executing.");
 
             job();
         });
diff --git a/listings/ch20-web-server/listing-20-23/src/lib.rs b/listings/ch20-web-server/listing-20-23/src/lib.rs
index 6ccaee73f6..0da9a9c9b5 100644
--- a/listings/ch20-web-server/listing-20-23/src/lib.rs
+++ b/listings/ch20-web-server/listing-20-23/src/lib.rs
@@ -86,12 +86,12 @@ impl Worker {
 
             match message {
                 Message::NewJob(job) => {
-                    println!("Worker {} got a job; executing.", id);
+                    println!("Worker {id} got a job; executing.");
 
                     job();
                 }
                 Message::Terminate => {
-                    println!("Worker {} was told to terminate.", id);
+                    println!("Worker {id} was told to terminate.");
 
                     break;
                 }
diff --git a/listings/ch20-web-server/listing-20-24/src/lib.rs b/listings/ch20-web-server/listing-20-24/src/lib.rs
index 747bff2b1f..e97637397d 100644
--- a/listings/ch20-web-server/listing-20-24/src/lib.rs
+++ b/listings/ch20-web-server/listing-20-24/src/lib.rs
@@ -83,12 +83,12 @@ impl Worker {
 
             match message {
                 Message::NewJob(job) => {
-                    println!("Worker {} got a job; executing.", id);
+                    println!("Worker {id} got a job; executing.");
 
                     job();
                 }
                 Message::Terminate => {
-                    println!("Worker {} was told to terminate.", id);
+                    println!("Worker {id} was told to terminate.");
 
                     break;
                 }
diff --git a/listings/ch20-web-server/listing-20-25/src/lib.rs b/listings/ch20-web-server/listing-20-25/src/lib.rs
index 68f4263057..8b27305dfe 100644
--- a/listings/ch20-web-server/listing-20-25/src/lib.rs
+++ b/listings/ch20-web-server/listing-20-25/src/lib.rs
@@ -81,12 +81,12 @@ impl Worker {
 
             match message {
                 Message::NewJob(job) => {
-                    println!("Worker {} got a job; executing.", id);
+                    println!("Worker {id} got a job; executing.");
 
                     job();
                 }
                 Message::Terminate => {
-                    println!("Worker {} was told to terminate.", id);
+                    println!("Worker {id} was told to terminate.");
 
                     break;
                 }
diff --git a/listings/ch20-web-server/no-listing-04-update-worker-definition/src/lib.rs b/listings/ch20-web-server/no-listing-04-update-worker-definition/src/lib.rs
index 1098330b3f..1ed8370125 100644
--- a/listings/ch20-web-server/no-listing-04-update-worker-definition/src/lib.rs
+++ b/listings/ch20-web-server/no-listing-04-update-worker-definition/src/lib.rs
@@ -66,7 +66,7 @@ impl Worker {
         let thread = thread::spawn(move || loop {
             let job = receiver.lock().unwrap().recv().unwrap();
 
-            println!("Worker {} got a job; executing.", id);
+            println!("Worker {id} got a job; executing.");
 
             job();
         });
diff --git a/listings/ch20-web-server/no-listing-05-fix-worker-new/src/lib.rs b/listings/ch20-web-server/no-listing-05-fix-worker-new/src/lib.rs
index 6bef23a16d..a9eff802cd 100644
--- a/listings/ch20-web-server/no-listing-05-fix-worker-new/src/lib.rs
+++ b/listings/ch20-web-server/no-listing-05-fix-worker-new/src/lib.rs
@@ -68,7 +68,7 @@ impl Worker {
         let thread = thread::spawn(move || loop {
             let job = receiver.lock().unwrap().recv().unwrap();
 
-            println!("Worker {} got a job; executing.", id);
+            println!("Worker {id} got a job; executing.");
 
             job();
         });
diff --git a/listings/ch20-web-server/no-listing-06-fix-threadpool-drop/src/lib.rs b/listings/ch20-web-server/no-listing-06-fix-threadpool-drop/src/lib.rs
index d5b38a635d..2f5b25b730 100644
--- a/listings/ch20-web-server/no-listing-06-fix-threadpool-drop/src/lib.rs
+++ b/listings/ch20-web-server/no-listing-06-fix-threadpool-drop/src/lib.rs
@@ -68,7 +68,7 @@ impl Worker {
         let thread = thread::spawn(move || loop {
             let job = receiver.lock().unwrap().recv().unwrap();
 
-            println!("Worker {} got a job; executing.", id);
+            println!("Worker {id} got a job; executing.");
 
             job();
         });
diff --git a/listings/ch20-web-server/no-listing-07-define-message-enum/src/lib.rs b/listings/ch20-web-server/no-listing-07-define-message-enum/src/lib.rs
index 46fb5f18d2..d4d74dfde3 100644
--- a/listings/ch20-web-server/no-listing-07-define-message-enum/src/lib.rs
+++ b/listings/ch20-web-server/no-listing-07-define-message-enum/src/lib.rs
@@ -73,7 +73,7 @@ impl Worker {
         let thread = thread::spawn(move || loop {
             let job = receiver.lock().unwrap().recv().unwrap();
 
-            println!("Worker {} got a job; executing.", id);
+            println!("Worker {id} got a job; executing.");
 
             job();
         });
diff --git a/listings/ch20-web-server/no-listing-08-final-code/src/lib.rs b/listings/ch20-web-server/no-listing-08-final-code/src/lib.rs
index 68f4263057..8b27305dfe 100644
--- a/listings/ch20-web-server/no-listing-08-final-code/src/lib.rs
+++ b/listings/ch20-web-server/no-listing-08-final-code/src/lib.rs
@@ -81,12 +81,12 @@ impl Worker {
 
             match message {
                 Message::NewJob(job) => {
-                    println!("Worker {} got a job; executing.", id);
+                    println!("Worker {id} got a job; executing.");
 
                     job();
                 }
                 Message::Terminate => {
-                    println!("Worker {} was told to terminate.", id);
+                    println!("Worker {id} was told to terminate.");
 
                     break;
                 }
diff --git a/redirects/loops.md b/redirects/loops.md
index 1686c115ee..30c7d4059f 100644
--- a/redirects/loops.md
+++ b/redirects/loops.md
@@ -14,17 +14,17 @@ loop {
 
 let mut number = 3;
 while number != 0 {
-    println!("{}!", number);
+    println!("{number}!");
     number = number - 1;
 }
 
 let a = [10, 20, 30, 40, 50];
 for element in a.iter() {
-    println!("the value is: {}", element);
+    println!("the value is: {element}");
 }
 ```
 
 ---
 
 You can find the latest version of this information
-[here](ch03-05-control-flow.html#repetition-with-loops).
\ No newline at end of file
+[here](ch03-05-control-flow.html#repetition-with-loops).