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.

Author: nrc

src/compiletest/compiletest.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 #![crate_type = "bin"]
-#![feature(phase)]
+#![feature(phase, slicing_syntax)]
 
 #![deny(warnings)]
 

src/doc/reference.md

@@ -3837,7 +3837,7 @@ type signature of `print`, and the cast expression in `main`.
 Within the body of an item that has type parameter declarations, the names of
 its type parameters are types:
 
-```
+```ignore
 fn map<A: Clone, B: Clone>(f: |A| -> B, xs: &[A]) -> Vec<B> {
     if xs.len() == 0 {
        return vec![];

src/libcollections/lib.rs

@@ -19,8 +19,9 @@
        html_root_url = "http://doc.rust-lang.org/master/",
        html_playground_url = "http://play.rust-lang.org/")]
 
+#![allow(unknown_features)]
 #![feature(macro_rules, default_type_params, phase, globs)]
-#![feature(unsafe_destructor, import_shadowing)]
+#![feature(unsafe_destructor, import_shadowing, slicing_syntax)]
 #![no_std]
 
 #[phase(plugin, link)] extern crate core;

src/libcollections/slice.rs

@@ -52,9 +52,12 @@
 //! interval `[a, b)`:
 //!
 //! ```rust
-//! let numbers = [0i, 1i, 2i];
-//! let last_numbers = numbers[1..3];
-//! // last_numbers is now &[1i, 2i]
+//! #![feature(slicing_syntax)]
+//! fn main() {
+//!     let numbers = [0i, 1i, 2i];
+//!     let last_numbers = numbers[1..3];
+//!     // last_numbers is now &[1i, 2i]
+//! }
 //! ```
 //!
 //! ## Implementations of other traits

src/libcore/lib.rs

@@ -57,8 +57,9 @@
        html_playground_url = "http://play.rust-lang.org/")]
 
 #![no_std]
+#![allow(unknown_features)]
 #![feature(globs, intrinsics, lang_items, macro_rules, phase)]
-#![feature(simd, unsafe_destructor)]
+#![feature(simd, unsafe_destructor, slicing_syntax)]
 #![deny(missing_doc)]
 
 mod macros;

src/libcore/ops.rs

@@ -684,7 +684,7 @@ pub trait IndexMut<Index, Result> {
  * A trivial implementation of `Slice`. When `Foo[..Foo]` happens, it ends up
  * calling `slice_to`, and therefore, `main` prints `Slicing!`.
  *
- * ```
+ * ```ignore
  * struct Foo;
  *
  * impl ::core::ops::Slice<Foo, Foo> for Foo {
@@ -734,7 +734,7 @@ pub trait Slice<Idx, Sized? Result> for Sized? {
  * A trivial implementation of `SliceMut`. When `Foo[Foo..]` happens, it ends up
  * calling `slice_from_mut`, and therefore, `main` prints `Slicing!`.
  *
- * ```
+ * ```ignore
  * struct Foo;
  *
  * impl ::core::ops::SliceMut<Foo, Foo> for Foo {
@@ -756,7 +756,7 @@ pub trait Slice<Idx, Sized? Result> for Sized? {
  *     }
  * }
  *
- * fn main() {
+ * pub fn main() {
  *     Foo[mut Foo..];
  * }
  * ```

src/libcoretest/lib.rs

@@ -7,7 +7,7 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-#![feature(globs, unsafe_destructor, macro_rules)]
+#![feature(globs, unsafe_destructor, macro_rules, slicing_syntax)]
 
 extern crate core;
 extern crate test;

src/libnative/lib.rs

@@ -57,7 +57,8 @@
 
 #![deny(unused_result, unused_must_use)]
 #![allow(non_camel_case_types, deprecated)]
-#![feature(default_type_params, lang_items)]
+#![allow(unknown_features)]
+#![feature(default_type_params, lang_items, slicing_syntax)]
 
 // NB this crate explicitly does *not* allow glob imports, please seriously
 //    consider whether they're needed before adding that feature here (the

src/libnum/lib.rs

@@ -43,7 +43,8 @@
 //!
 //! [newt]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method
 
-#![feature(macro_rules)]
+#![allow(unknown_features)]
+#![feature(macro_rules, slicing_syntax)]
 #![feature(default_type_params)]
 
 #![crate_name = "num"]

src/librbml/lib.rs

@@ -24,7 +24,8 @@
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/master/",
        html_playground_url = "http://play.rust-lang.org/")]
-#![feature(macro_rules, phase)]
+#![allow(unknown_features)]
+#![feature(macro_rules, phase, slicing_syntax)]
 #![allow(missing_doc)]
 
 extern crate serialize;

src/libregex/lib.rs

@@ -368,7 +368,8 @@
        html_root_url = "http://doc.rust-lang.org/master/",
        html_playground_url = "http://play.rust-lang.org/")]
 
-#![feature(macro_rules, phase)]
+#![allow(unknown_features)]
+#![feature(macro_rules, phase, slicing_syntax)]
 #![deny(missing_doc)]
 
 #[cfg(test)]

src/librustc/lib.rs

@@ -29,8 +29,9 @@ This API is completely unstable and subject to change.
       html_root_url = "http://doc.rust-lang.org/master/")]
 
 #![allow(deprecated)]
+#![allow(unknown_features)]
 #![feature(macro_rules, globs, struct_variant, quote)]
-#![feature(default_type_params, phase, unsafe_destructor)]
+#![feature(default_type_params, phase, unsafe_destructor, slicing_syntax)]
 
 #![feature(rustc_diagnostic_macros)]
 #![feature(import_shadowing)]

src/librustc_back/lib.rs

@@ -31,7 +31,8 @@
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
       html_root_url = "http://doc.rust-lang.org/")]
 
-#![feature(globs, phase, macro_rules)]
+#![allow(unknown_features)]
+#![feature(globs, phase, macro_rules, slicing_syntax)]
 
 #[phase(plugin, link)]
 extern crate log;

src/librustdoc/lib.rs

@@ -15,7 +15,8 @@
 #![crate_type = "dylib"]
 #![crate_type = "rlib"]
 
-#![feature(globs, struct_variant, macro_rules, phase)]
+#![allow(unknown_features)]
+#![feature(globs, struct_variant, macro_rules, phase, slicing_syntax)]
 
 extern crate arena;
 extern crate debug;

src/librustrt/lib.rs

@@ -16,9 +16,10 @@
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/master/")]
 
+#![allow(unknown_features)]
 #![feature(macro_rules, phase, globs, thread_local, asm)]
 #![feature(linkage, lang_items, unsafe_destructor, default_type_params)]
-#![feature(import_shadowing)]
+#![feature(import_shadowing, slicing_syntax)]
 #![no_std]
 #![experimental]
 

src/libserialize/lib.rs

@@ -23,7 +23,8 @@ Core encoding and decoding interfaces.
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/master/",
        html_playground_url = "http://play.rust-lang.org/")]
-#![feature(macro_rules, default_type_params, phase)]
+#![allow(unknown_features)]
+#![feature(macro_rules, default_type_params, phase, slicing_syntax)]
 
 // test harness access
 #[cfg(test)]

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>,

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, 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]

src/libsyntax/feature_gate.rs

@@ -70,6 +70,7 @@ static KNOWN_FEATURES: &'static [(&'static str, Status)] = &[
     ("tuple_indexing", Active),
     ("associated_types", Active),
     ("visible_private_types", Active),
+    ("slicing_syntax", Active),
 
     ("if_let", Active),
 
@@ -350,6 +351,11 @@ impl<'a, 'v> Visitor<'v> for Context<'a> {
                 self.gate_feature("if_let", e.span,
                                   "`if let` syntax is experimental");
             }
+            ast::ExprSlice(..) => {
+                self.gate_feature("slicing_syntax",
+                                  e.span,
+                                  "slicing syntax is experimental");
+            }
             _ => {}
         }
         visit::walk_expr(self, e);

src/libsyntax/lib.rs

@@ -23,7 +23,8 @@
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/master/")]
 
-#![feature(macro_rules, globs, default_type_params, phase)]
+#![allow(unknown_features)]
+#![feature(macro_rules, globs, default_type_params, phase, slicing_syntax)]
 #![feature(quote, struct_variant, unsafe_destructor, import_shadowing)]
 #![allow(deprecated)]
 

src/libterm/lib.rs

@@ -49,7 +49,8 @@
        html_root_url = "http://doc.rust-lang.org/master/",
        html_playground_url = "http://play.rust-lang.org/")]
 
-#![feature(macro_rules, phase)]
+#![allow(unknown_features)]
+#![feature(macro_rules, phase, slicing_syntax)]
 
 #![deny(missing_doc)]
 

src/test/bench/shootout-fannkuch-redux.rs

@@ -38,6 +38,8 @@
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 // OF THE POSSIBILITY OF SUCH DAMAGE.
 
+#![feature(slicing_syntax)]
+
 use std::{cmp, iter, mem};
 use std::sync::Future;
 

src/test/bench/shootout-fasta-redux.rs

@@ -38,6 +38,8 @@
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 // OF THE POSSIBILITY OF SUCH DAMAGE.
 
+#![feature(slicing_syntax)]
+
 use std::cmp::min;
 use std::io::{stdout, IoResult};
 use std::os;

src/test/bench/shootout-fasta.rs

@@ -38,6 +38,8 @@
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 // OF THE POSSIBILITY OF SUCH DAMAGE.
 
+#![feature(slicing_syntax)]
+
 use std::io;
 use std::io::{BufferedWriter, File};
 use std::cmp::min;

src/test/bench/shootout-k-nucleotide-pipes.rs

@@ -13,6 +13,8 @@
 
 // multi tasking k-nucleotide
 
+#![feature(slicing_syntax)]
+
 extern crate collections;
 
 use std::collections::HashMap;

src/test/bench/shootout-k-nucleotide.rs

@@ -40,6 +40,8 @@
 
 // ignore-android see #10393 #13206
 
+#![feature(slicing_syntax)]
+
 use std::string::String;
 use std::slice;
 use std::sync::{Arc, Future};

src/test/bench/shootout-regex-dna.rs

@@ -41,7 +41,7 @@
 // ignore-stage1
 // ignore-cross-compile #12102
 
-#![feature(macro_rules, phase)]
+#![feature(macro_rules, phase, slicing_syntax)]
 
 extern crate regex;
 #[phase(plugin)]extern crate regex_macros;

src/test/bench/shootout-reverse-complement.rs

@@ -41,6 +41,8 @@
 // ignore-pretty very bad with line comments
 // ignore-android doesn't terminate?
 
+#![feature(slicing_syntax)]
+
 use std::iter::range_step;
 use std::io::{stdin, stdout, File};
 

src/test/compile-fail/issue-15730.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(slicing_syntax)]
+
 fn main() {
     let mut array = [1, 2, 3];
 //~^ ERROR cannot determine a type for this local variable: cannot determine the type of this integ

src/test/compile-fail/slice-2.rs

@@ -10,6 +10,8 @@
 
 // Test that slicing syntax gives errors if we have not implemented the trait.
 
+#![feature(slicing_syntax)]
+
 struct Foo;
 
 fn main() {

src/test/compile-fail/slice-borrow.rs

@@ -10,6 +10,8 @@
 
 // Test slicing expressions doesn't defeat the borrow checker.
 
+#![feature(slicing_syntax)]
+
 fn main() {
     let y;
     {

src/test/compile-fail/slice-mut-2.rs

@@ -10,6 +10,8 @@
 
 // Test mutability and slicing syntax.
 
+#![feature(slicing_syntax)]
+
 fn main() {
     let x: &[int] = &[1, 2, 3, 4, 5];
     // Can't mutably slice an immutable slice

src/test/compile-fail/slice-mut.rs

@@ -10,6 +10,8 @@
 
 // Test mutability and slicing syntax.
 
+#![feature(slicing_syntax)]
+
 fn main() {
     let x: &[int] = &[1, 2, 3, 4, 5];
     // Immutable slices are not mutable.

src/test/debuginfo/vec-slices.rs

@@ -80,6 +80,7 @@
 // lldb-check:[...]$5 = &[AStruct { x: 10, y: 11, z: 12 }, AStruct { x: 13, y: 14, z: 15 }]
 
 #![allow(unused_variable)]
+#![feature(slicing_syntax)]
 
 struct AStruct {
     x: i16,