From a093957f43703555d02aaa2b8fd64ea686e1cd88 Mon Sep 17 00:00:00 2001
From: Tamir Duberstein <tamird@google.com>
Date: Sun, 4 Oct 2020 21:46:49 +0000
Subject: [PATCH] Avoid unused return

---
 library/std/src/net/parser.rs | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/library/std/src/net/parser.rs b/library/std/src/net/parser.rs
index 3a5fd8f6f5d..87ff18411c7 100644
--- a/library/std/src/net/parser.rs
+++ b/library/std/src/net/parser.rs
@@ -75,9 +75,12 @@ impl<'a> Parser<'a> {
         })
     }
 
-    /// Read the next character from the input if it matches the target
-    fn read_given_char(&mut self, target: char) -> Option<char> {
-        self.read_atomically(|p| p.read_char().filter(|&c| c == target))
+    #[must_use]
+    /// Read the next character from the input if it matches the target.
+    fn read_given_char(&mut self, target: char) -> Option<()> {
+        self.read_atomically(|p| {
+            p.read_char().and_then(|c| if c == target { Some(()) } else { None })
+        })
     }
 
     /// Helper for reading separators in an indexed loop. Reads the separator
@@ -90,7 +93,7 @@ impl<'a> Parser<'a> {
     {
         self.read_atomically(move |p| {
             if index > 0 {
-                let _ = p.read_given_char(sep)?;
+                p.read_given_char(sep)?;
             }
             inner(p)
         })
@@ -187,8 +190,8 @@ impl<'a> Parser<'a> {
 
             // read `::` if previous code parsed less than 8 groups
             // `::` indicates one or more groups of 16 bits of zeros
-            let _ = p.read_given_char(':')?;
-            let _ = p.read_given_char(':')?;
+            p.read_given_char(':')?;
+            p.read_given_char(':')?;
 
             // Read the back part of the address. The :: must contain at least one
             // set of zeroes, so our max length is 7.
@@ -211,7 +214,7 @@ impl<'a> Parser<'a> {
     /// Read a : followed by a port in base 10.
     fn read_port(&mut self) -> Option<u16> {
         self.read_atomically(|p| {
-            let _ = p.read_given_char(':')?;
+            p.read_given_char(':')?;
             p.read_number(10, None)
         })
     }
@@ -228,9 +231,9 @@ impl<'a> Parser<'a> {
     /// Read an IPV6 address with a port
     fn read_socket_addr_v6(&mut self) -> Option<SocketAddrV6> {
         self.read_atomically(|p| {
-            let _ = p.read_given_char('[')?;
+            p.read_given_char('[')?;
             let ip = p.read_ipv6_addr()?;
-            let _ = p.read_given_char(']')?;
+            p.read_given_char(']')?;
 
             let port = p.read_port()?;
             Some(SocketAddrV6::new(ip, port, 0, 0))