docs: replace match guards by pattern matching in examples (#7035)

Author: barafael

README.md

@@ -78,7 +78,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
             loop {
                 let n = match socket.read(&mut buf).await {
                     // socket closed
-                    Ok(n) if n == 0 => return,
+                    Ok(0) => return,
                     Ok(n) => n,
                     Err(e) => {
                         eprintln!("failed to read from socket; err = {:?}", e);

tokio/README.md

@@ -78,7 +78,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
             loop {
                 let n = match socket.read(&mut buf).await {
                     // socket closed
-                    Ok(n) if n == 0 => return,
+                    Ok(0) => return,
                     Ok(n) => n,
                     Err(e) => {
                         eprintln!("failed to read from socket; err = {:?}", e);

tokio/src/lib.rs

@@ -284,7 +284,7 @@
 //!             loop {
 //!                 let n = match socket.read(&mut buf).await {
 //!                     // socket closed
-//!                     Ok(n) if n == 0 => return,
+//!                     Ok(0) => return,
 //!                     Ok(n) => n,
 //!                     Err(e) => {
 //!                         eprintln!("failed to read from socket; err = {:?}", e);

tokio/src/runtime/mod.rs

@@ -36,7 +36,7 @@
 //!             loop {
 //!                 let n = match socket.read(&mut buf).await {
 //!                     // socket closed
-//!                     Ok(n) if n == 0 => return,
+//!                     Ok(0) => return,
 //!                     Ok(n) => n,
 //!                     Err(e) => {
 //!                         println!("failed to read from socket; err = {:?}", e);
@@ -84,7 +84,7 @@
 //!                 loop {
 //!                     let n = match socket.read(&mut buf).await {
 //!                         // socket closed
-//!                         Ok(n) if n == 0 => return,
+//!                         Ok(0) => return,
 //!                         Ok(n) => n,
 //!                         Err(e) => {
 //!                             println!("failed to read from socket; err = {:?}", e);