Auto merge of #32390 - japaric:untry, r=pnkfelix

convert 99.9% of `try!`s to `?`s

The first commit is an automated conversion using the [untry] tool and the following command:

```
$ find -name '*.rs' -type f | xargs untry
```

at the root of the Rust repo.

[untry]: https://github.com/japaric/untry

cc @rust-lang/lang @alexcrichton @brson

4 files changed, 9 insertions, 9 deletions

diff --git a/src/libstd/net/addr.rs b/src/libstd/net/addr.rs
index 78da9412212..273a2004fc0 100644
--- a/src/libstd/net/addr.rs
+++ b/src/libstd/net/addr.rs
@@ -431,13 +431,13 @@ impl ToSocketAddrs for (Ipv6Addr, u16) {
 }
 
 fn resolve_socket_addr(s: &str, p: u16) -> io::Result<vec::IntoIter<SocketAddr>> {
-    let ips = try!(lookup_host(s));
-    let v: Vec<_> = try!(ips.map(|a| {
+    let ips = lookup_host(s)?;
+    let v: Vec<_> = ips.map(|a| {
         a.map(|mut a| {
             a.set_port(p);
             a
         })
-    }).collect());
+    }).collect()?;
     Ok(v.into_iter())
 }
 
diff --git a/src/libstd/net/ip.rs b/src/libstd/net/ip.rs
index 934d0468a38..541daf86c31 100644
--- a/src/libstd/net/ip.rs
+++ b/src/libstd/net/ip.rs
@@ -487,16 +487,16 @@ impl fmt::Display for Ipv6Addr {
                 if zeros_len > 1 {
                     fn fmt_subslice(segments: &[u16], fmt: &mut fmt::Formatter) -> fmt::Result {
                         if !segments.is_empty() {
-                            try!(write!(fmt, "{:x}", segments[0]));
+                            write!(fmt, "{:x}", segments[0])?;
                             for &seg in &segments[1..] {
-                                try!(write!(fmt, ":{:x}", seg));
+                                write!(fmt, ":{:x}", seg)?;
                             }
                         }
                         Ok(())
                     }
 
-                    try!(fmt_subslice(&self.segments()[..zeros_at], fmt));
-                    try!(fmt.write_str("::"));
+                    fmt_subslice(&self.segments()[..zeros_at], fmt)?;
+                    fmt.write_str("::")?;
                     fmt_subslice(&self.segments()[zeros_at + zeros_len..], fmt)
                 } else {
                     let &[a, b, c, d, e, f, g, h] = &self.segments();
diff --git a/src/libstd/net/mod.rs b/src/libstd/net/mod.rs
index 22332b709ce..45070460282 100644
--- a/src/libstd/net/mod.rs
+++ b/src/libstd/net/mod.rs
@@ -74,7 +74,7 @@ fn each_addr<A: ToSocketAddrs, F, T>(addr: A, mut f: F) -> io::Result<T>
     where F: FnMut(&SocketAddr) -> io::Result<T>
 {
     let mut last_err = None;
-    for addr in try!(addr.to_socket_addrs()) {
+    for addr in addr.to_socket_addrs()? {
         match f(&addr) {
             Ok(l) => return Ok(l),
             Err(e) => last_err = Some(e),
diff --git a/src/libstd/net/udp.rs b/src/libstd/net/udp.rs
index bce82565fdf..da1cf115e8d 100644
--- a/src/libstd/net/udp.rs
+++ b/src/libstd/net/udp.rs
@@ -70,7 +70,7 @@ impl UdpSocket {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn send_to<A: ToSocketAddrs>(&self, buf: &[u8], addr: A)
                                      -> io::Result<usize> {
-        match try!(addr.to_socket_addrs()).next() {
+        match addr.to_socket_addrs()?.next() {
             Some(addr) => self.0.send_to(buf, &addr),
             None => Err(Error::new(ErrorKind::InvalidInput,
                                    "no addresses to send data to")),