Auto merge of #46602 - mbrubeck:try, r=kennytm

Replace option_try macros and match with ? operator

None

6 files changed, 13 insertions, 35 deletions

diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index 51698ce7c17..7f0e5a8d2aa 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -1152,13 +1152,9 @@ impl<'a, T, S> Iterator for Intersection<'a, T, S>
 
     fn next(&mut self) -> Option<&'a T> {
         loop {
-            match self.iter.next() {
-                None => return None,
-                Some(elt) => {
-                    if self.other.contains(elt) {
-                        return Some(elt);
-                    }
-                }
+            let elt = self.iter.next()?;
+            if self.other.contains(elt) {
+                return Some(elt);
             }
         }
     }
@@ -1202,13 +1198,9 @@ impl<'a, T, S> Iterator for Difference<'a, T, S>
 
     fn next(&mut self) -> Option<&'a T> {
         loop {
-            match self.iter.next() {
-                None => return None,
-                Some(elt) => {
-                    if !self.other.contains(elt) {
-                        return Some(elt);
-                    }
-                }
+            let elt = self.iter.next()?;
+            if !self.other.contains(elt) {
+                return Some(elt);
             }
         }
     }
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index b7a3695b470..9c401d7663f 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -2019,10 +2019,9 @@ impl<R: Read> Iterator for Chars<R> {
     type Item = result::Result<char, CharsError>;
 
     fn next(&mut self) -> Option<result::Result<char, CharsError>> {
-        let first_byte = match read_one_byte(&mut self.inner) {
-            None => return None,
-            Some(Ok(b)) => b,
-            Some(Err(e)) => return Some(Err(CharsError::Other(e))),
+        let first_byte = match read_one_byte(&mut self.inner)? {
+            Ok(b) => b,
+            Err(e) => return Some(Err(CharsError::Other(e))),
         };
         let width = core_str::utf8_char_width(first_byte);
         if width == 1 { return Some(Ok(first_byte as char)) }
diff --git a/src/libstd/net/parser.rs b/src/libstd/net/parser.rs
index 7d7c67ff3f9..9f7125fb935 100644
--- a/src/libstd/net/parser.rs
+++ b/src/libstd/net/parser.rs
@@ -170,11 +170,7 @@ impl<'a> Parser<'a> {
                 return None;
             }
 
-            let octet = self.read_number(10, 3, 0x100).map(|n| n as u8);
-            match octet {
-                Some(d) => bs[i] = d,
-                None => return None,
-            };
+            bs[i] = self.read_number(10, 3, 0x100).map(|n| n as u8)?;
             i += 1;
         }
         Some(Ipv4Addr::new(bs[0], bs[1], bs[2], bs[3]))
diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index 9da33f5adac..cb249af4254 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -255,10 +255,7 @@ pub mod guard {
 
     pub unsafe fn init() -> Option<usize> {
         let psize = os::page_size();
-        let mut stackaddr = match get_stack_start() {
-            Some(addr) => addr,
-            None => return None,
-        };
+        let mut stackaddr = get_stack_start()?;
 
         // Ensure stackaddr is page aligned! A parent process might
         // have reset RLIMIT_STACK to be non-page aligned. The
diff --git a/src/libstd/sys_common/net.rs b/src/libstd/sys_common/net.rs
index c76b0bcf1c9..c70b39995eb 100644
--- a/src/libstd/sys_common/net.rs
+++ b/src/libstd/sys_common/net.rs
@@ -136,10 +136,7 @@ impl Iterator for LookupHost {
     fn next(&mut self) -> Option<SocketAddr> {
         loop {
             unsafe {
-                let cur = match self.cur.as_ref() {
-                    None => return None,
-                    Some(c) => c,
-                };
+                let cur = self.cur.as_ref()?;
                 self.cur = cur.ai_next;
                 match sockaddr_to_addr(mem::transmute(cur.ai_addr),
                                        cur.ai_addrlen as usize)
diff --git a/src/libstd/sys_common/wtf8.rs b/src/libstd/sys_common/wtf8.rs
index e212b5006f2..b2fc559bb37 100644
--- a/src/libstd/sys_common/wtf8.rs
+++ b/src/libstd/sys_common/wtf8.rs
@@ -578,10 +578,7 @@ impl Wtf8 {
     fn next_surrogate(&self, mut pos: usize) -> Option<(usize, u16)> {
         let mut iter = self.bytes[pos..].iter();
         loop {
-            let b = match iter.next() {
-                None => return None,
-                Some(&b) => b,
-            };
+            let b = *iter.next()?;
             if b < 0x80 {
                 pos += 1;
             } else if b < 0xE0 {