Put slicing syntax behind a feature gate.

[breaking-change]

If you are using slicing syntax you will need to add #![feature(slicing_syntax)] to your crate.

2 files changed, 20 insertions, 16 deletions

diff --git a/src/libstd/io/net/udp.rs b/src/libstd/io/net/udp.rs
index 4dd6f448ee5..b8fb187548c 100644
--- a/src/libstd/io/net/udp.rs
+++ b/src/libstd/io/net/udp.rs
@@ -35,26 +35,29 @@ use rt::rtio;
 ///
 /// ```rust,no_run
 /// # #![allow(unused_must_use)]
+/// #![feature(slicing_syntax)]
+///
 /// use std::io::net::udp::UdpSocket;
 /// use std::io::net::ip::{Ipv4Addr, SocketAddr};
+/// fn main() {
+///     let addr = SocketAddr { ip: Ipv4Addr(127, 0, 0, 1), port: 34254 };
+///     let mut socket = match UdpSocket::bind(addr) {
+///         Ok(s) => s,
+///         Err(e) => fail!("couldn't bind socket: {}", e),
+///     };
 ///
-/// let addr = SocketAddr { ip: Ipv4Addr(127, 0, 0, 1), port: 34254 };
-/// let mut socket = match UdpSocket::bind(addr) {
-///     Ok(s) => s,
-///     Err(e) => fail!("couldn't bind socket: {}", e),
-/// };
-///
-/// let mut buf = [0, ..10];
-/// match socket.recv_from(buf) {
-///     Ok((amt, src)) => {
-///         // Send a reply to the socket we received data from
-///         let buf = buf[mut ..amt];
-///         buf.reverse();
-///         socket.send_to(buf, src);
+///     let mut buf = [0, ..10];
+///     match socket.recv_from(buf) {
+///         Ok((amt, src)) => {
+///             // Send a reply to the socket we received data from
+///             let buf = buf[mut ..amt];
+///             buf.reverse();
+///             socket.send_to(buf, src);
+///         }
+///         Err(e) => println!("couldn't receive a datagram: {}", e)
 ///     }
-///     Err(e) => println!("couldn't receive a datagram: {}", e)
+///     drop(socket); // close the socket
 /// }
-/// drop(socket); // close the socket
 /// ```
 pub struct UdpSocket {
     obj: Box<RtioUdpSocket + Send>,
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 7304871cf21..82de55efad6 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -105,9 +105,10 @@
        html_root_url = "http://doc.rust-lang.org/master/",
        html_playground_url = "http://play.rust-lang.org/")]
 
+#![allow(unknown_features)]
 #![feature(macro_rules, globs, managed_boxes, linkage)]
 #![feature(default_type_params, phase, lang_items, unsafe_destructor)]
-#![feature(import_shadowing)]
+#![feature(import_shadowing, slicing_syntax)]
 
 // Don't link to std. We are std.
 #![no_std]