Use more modern interpolation

Author: samueltardieu

examples/03_01_async_await/src/lib.rs

@@ -62,12 +62,12 @@ async fn blocks() {
 
     let future_one = async {
         // ...
-        println!("{}", my_string);
+        println!("{my_string}");
     };
 
     let future_two = async {
         // ...
-        println!("{}", my_string);
+        println!("{my_string}");
     };
 
     // Run both futures to completion, printing "foo" twice:
@@ -84,7 +84,7 @@ fn move_block() -> impl Future<Output = ()> {
     let my_string = "foo".to_string();
     async move {
         // ...
-        println!("{}", my_string);
+        println!("{my_string}");
     }
 }
 // ANCHOR_END: async_move_examples

examples/09_01_sync_tcp_server/src/main.rs

@@ -33,7 +33,7 @@ fn handle_connection(mut stream: TcpStream) {
 
     // Write response back to the stream,
     // and flush the stream to ensure the response is sent back to the client
-    let response = format!("{}{}", status_line, contents);
+    let response = format!("{status_line}{contents}");
     stream.write(response.as_bytes()).unwrap();
     stream.flush().unwrap();
 }

examples/09_03_slow_request/src/main.rs

@@ -33,7 +33,7 @@ async fn handle_connection(mut stream: TcpStream) {
     };
     let contents = fs::read_to_string(filename).unwrap();
 
-    let response = format!("{}{}", status_line, contents);
+    let response = format!("{status_line}{contents}");
     stream.write(response.as_bytes()).unwrap();
     stream.flush().unwrap();
 }

examples/09_05_final_tcp_server/src/main.rs

@@ -33,7 +33,7 @@ async fn handle_connection(mut stream: impl Read + Write + Unpin) {
         ("HTTP/1.1 404 NOT FOUND\r\n\r\n", "404.html")
     };
     let contents = fs::read_to_string(filename).unwrap();
-    let response = format!("{}{}", status_line, contents);
+    let response = format!("{status_line}{contents}");
     stream.write(response.as_bytes()).await.unwrap();
     stream.flush().await.unwrap();
 }