rollup merge of #20723: pnkfelix/feature-gate-box-syntax

Conflicts:
	src/compiletest/compiletest.rs
	src/libcollections/lib.rs
	src/libserialize/lib.rs
	src/libsyntax/feature_gate.rs

src/compiletest/compiletest.rs

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

src/liballoc/boxed.rs

@@ -49,6 +49,15 @@ pub static HEAP: () = ();
 #[stable]
 pub struct Box<T>(Unique<T>);
 
+#[unstable]
+impl<T> Box<T> {
+    /// Moves `x` into a freshly allocated box on the global exchange heap.
+    #[unstable]
+    pub fn new(x: T) -> Box<T> {
+        box x
+    }
+}
+
 #[stable]
 impl<T: Default> Default for Box<T> {
     #[stable]
@@ -186,27 +195,27 @@ impl<T: ?Sized> DerefMut for Box<T> {
 mod test {
     #[test]
     fn test_owned_clone() {
-        let a = box 5i;
+        let a = Box::new(5i);
         let b: Box<int> = a.clone();
         assert!(a == b);
     }
 
     #[test]
     fn any_move() {
-        let a = box 8u as Box<Any>;
-        let b = box Test as Box<Any>;
+        let a = Box::new(8u) as Box<Any>;
+        let b = Box::new(Test) as Box<Any>;
 
         match a.downcast::<uint>() {
-            Ok(a) => { assert!(a == box 8u); }
+            Ok(a) => { assert!(a == Box::new(8u)); }
             Err(..) => panic!()
         }
         match b.downcast::<Test>() {
-            Ok(a) => { assert!(a == box Test); }
+            Ok(a) => { assert!(a == Box::new(Test)); }
             Err(..) => panic!()
         }
 
-        let a = box 8u as Box<Any>;
-        let b = box Test as Box<Any>;
+        let a = Box::new(8u) as Box<Any>;
+        let b = Box::new(Test) as Box<Any>;
 
         assert!(a.downcast::<Box<Test>>().is_err());
         assert!(b.downcast::<Box<uint>>().is_err());
@@ -214,8 +223,8 @@ mod test {
 
     #[test]
     fn test_show() {
-        let a = box 8u as Box<Any>;
-        let b = box Test as Box<Any>;
+        let a = Box::new(8u) as Box<Any>;
+        let b = Box::new(Test) as Box<Any>;
         let a_str = a.to_str();
         let b_str = b.to_str();
         assert_eq!(a_str, "Box<Any>");
@@ -232,6 +241,6 @@ mod test {
     #[test]
     fn deref() {
         fn homura<T: Deref<Target=i32>>(_: T) { }
-        homura(box 765i32);
+        homura(Box::new(765i32));
     }
 }

src/liballoc/lib.rs

@@ -67,6 +67,7 @@
 #![no_std]
 #![allow(unknown_features)]
 #![feature(lang_items, unsafe_destructor)]
+#![feature(box_syntax)]
 
 #[macro_use]
 extern crate core;

src/libcollections/lib.rs

@@ -24,6 +24,7 @@
 
 #![allow(unknown_features)]
 #![feature(unsafe_destructor, slicing_syntax)]
+#![feature(box_syntax)]
 #![feature(unboxed_closures)]
 #![feature(old_impl_check)]
 #![no_std]

src/liblog/lib.rs

@@ -164,7 +164,10 @@
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/nightly/",
        html_playground_url = "http://play.rust-lang.org/")]
+
+#![allow(unknown_features)]
 #![feature(slicing_syntax)]
+#![feature(box_syntax)]
 #![deny(missing_docs)]
 
 extern crate regex;

src/libregex/lib.rs

@@ -25,6 +25,7 @@
 
 #![allow(unknown_features)]
 #![feature(slicing_syntax)]
+#![feature(box_syntax)]
 #![deny(missing_docs)]
 
 #[cfg(test)]

src/librustc/lib.rs

@@ -26,6 +26,7 @@
 #![allow(unknown_features)]
 #![feature(quote)]
 #![feature(slicing_syntax, unsafe_destructor)]
+#![feature(box_syntax)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(old_impl_check)]
 

src/librustc_driver/lib.rs

@@ -23,8 +23,10 @@
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
       html_root_url = "http://doc.rust-lang.org/nightly/")]
 
+#![allow(unknown_features)]
 #![feature(quote)]
 #![feature(slicing_syntax, unsafe_destructor)]
+#![feature(box_syntax)]
 #![feature(rustc_diagnostic_macros)]
 
 extern crate arena;

src/librustc_llvm/lib.rs

@@ -22,7 +22,9 @@
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/nightly/")]
 
+#![allow(unknown_features)]
 #![feature(link_args)]
+#![feature(box_syntax)]
 
 extern crate libc;
 

src/librustc_trans/lib.rs

@@ -23,8 +23,10 @@
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
       html_root_url = "http://doc.rust-lang.org/nightly/")]
 
+#![allow(unknown_features)]
 #![feature(quote)]
 #![feature(slicing_syntax, unsafe_destructor)]
+#![feature(box_syntax)]
 #![feature(rustc_diagnostic_macros)]
 
 extern crate arena;

src/librustc_typeck/lib.rs

@@ -72,8 +72,10 @@ This API is completely unstable and subject to change.
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
       html_root_url = "http://doc.rust-lang.org/nightly/")]
 
+#![allow(unknown_features)]
 #![feature(quote)]
 #![feature(slicing_syntax, unsafe_destructor)]
+#![feature(box_syntax)]
 #![feature(rustc_diagnostic_macros)]
 #![allow(non_camel_case_types)]
 

src/librustdoc/lib.rs

@@ -18,6 +18,7 @@
        html_root_url = "http://doc.rust-lang.org/nightly/",
        html_playground_url = "http://play.rust-lang.org/")]
 #![feature(slicing_syntax)]
+#![feature(box_syntax)]
 
 extern crate arena;
 extern crate getopts;

src/libserialize/lib.rs

@@ -25,6 +25,7 @@ Core encoding and decoding interfaces.
        html_playground_url = "http://play.rust-lang.org/")]
 #![allow(unknown_features)]
 #![cfg_attr(stage0, allow(unused_attributes))]
+#![feature(box_syntax)]
 #![feature(old_impl_check)]
 #![feature(slicing_syntax)]
 

src/libstd/lib.rs

@@ -108,6 +108,7 @@
 #![feature(linkage, thread_local, asm)]
 #![feature(lang_items, unsafe_destructor)]
 #![feature(slicing_syntax, unboxed_closures)]
+#![feature(box_syntax)]
 #![feature(old_impl_check)]
 
 // Don't link to std. We are std.

src/libsyntax/feature_gate.rs

@@ -69,7 +69,8 @@ static KNOWN_FEATURES: &'static [(&'static str, Status)] = &[
     ("tuple_indexing", Accepted),
     ("associated_types", Accepted),
     ("visible_private_types", Active),
-    ("slicing_syntax", Accepted),
+    ("slicing_syntax", Active),
+    ("box_syntax", Active),
 
     ("if_let", Accepted),
     ("while_let", Accepted),
@@ -337,6 +338,15 @@ impl<'a, 'v> Visitor<'v> for PostExpansionVisitor<'a> {
     }
 
     fn visit_expr(&mut self, e: &ast::Expr) {
+        match e.node {
+            ast::ExprBox(..) | ast::ExprUnary(ast::UnOp::UnUniq, _) => {
+                self.gate_feature("box_syntax",
+                                  e.span,
+                                  "box expression syntax is experimental in alpha release; \
+                                   you can call `Box::new` instead.");
+            }
+            _ => {}
+        }
         visit::walk_expr(self, e);
     }
 
@@ -357,6 +367,11 @@ impl<'a, 'v> Visitor<'v> for PostExpansionVisitor<'a> {
                                    but at the end of a slice (e.g. \
                                    `[0, ..xs, 0]` are experimental")
             }
+            ast::PatBox(..) => {
+                self.gate_feature("box_syntax",
+                                  pattern.span,
+                                  "box pattern syntax is experimental in alpha release");
+            }
             _ => {}
         }
         visit::walk_pat(self, pattern)

src/libsyntax/lib.rs

@@ -25,6 +25,7 @@
 
 #![allow(unknown_features)]
 #![feature(slicing_syntax)]
+#![feature(box_syntax)]
 #![feature(quote, unsafe_destructor)]
 
 extern crate arena;

src/libterm/lib.rs

@@ -50,6 +50,7 @@
 
 #![allow(unknown_features)]
 #![feature(slicing_syntax)]
+#![feature(box_syntax)]
 #![deny(missing_docs)]
 
 #[macro_use] extern crate log;

src/libtest/lib.rs

@@ -31,7 +31,9 @@
 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/nightly/")]
+#![allow(unknown_features)]
 #![feature(asm, slicing_syntax)]
+#![feature(box_syntax)]
 
 extern crate getopts;
 extern crate regex;

src/test/auxiliary/cci_nested_lib.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 use std::cell::RefCell;
 

src/test/auxiliary/issue-2380.rs

@@ -11,6 +11,8 @@
 #![crate_name="a"]
 #![crate_type = "lib"]
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 pub trait i<T> { }
 

src/test/auxiliary/method_self_arg1.rs

@@ -10,6 +10,9 @@
 
 #![crate_type = "lib"]
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 static mut COUNT: u64 = 1;
 
 pub fn get_count() -> u64 { unsafe { COUNT } }

src/test/auxiliary/method_self_arg2.rs

@@ -10,6 +10,9 @@
 
 #![crate_type = "lib"]
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 static mut COUNT: u64 = 1;
 
 pub fn get_count() -> u64 { unsafe { COUNT } }

src/test/compile-fail/autoderef-full-lval.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct clam {
     x: Box<isize>,
     y: Box<isize>,

src/test/compile-fail/borrow-tuple-fields.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct Foo(Box<int>, int);
 
 struct Bar(int, int);

src/test/compile-fail/borrowck-array-double-move.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn f() {
     let mut a = [box 0i, box 1i];
     drop(a[0]);

src/test/compile-fail/borrowck-loan-in-overloaded-op.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
+
 use std::ops::Add;
 
 #[derive(Clone)]

src/test/compile-fail/borrowck-vec-pattern-nesting.rs

@@ -9,6 +9,7 @@
 // except according to those terms.
 
 #![feature(advanced_slice_patterns)]
+#![feature(box_syntax)]
 
 fn a() {
     let mut vec = [box 1i, box 2, box 3];

src/test/compile-fail/destructure-trait-ref.rs

@@ -11,6 +11,8 @@
 // The regression test for #15031 to make sure destructuring trait
 // reference work properly.
 
+#![feature(box_syntax)]
+
 trait T {}
 impl T for int {}
 

src/test/compile-fail/feature-gate-box-expr.rs

@@ -0,0 +1,23 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <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.
+
+fn main() {
+    use std::boxed::HEAP;
+
+    let x = box 'c'; //~ ERROR box expression syntax is experimental in alpha release
+    println!("x: {}", x);
+
+    let x = box () 'c'; //~ ERROR box expression syntax is experimental in alpha release
+    println!("x: {}", x);
+
+    let x = box (HEAP) 'c'; //~ ERROR box expression syntax is experimental in alpha release
+    println!("x: {}", x);
+}
+

src/test/compile-fail/feature-gate-box-pat.rs

@@ -0,0 +1,14 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <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.
+
+fn main() {
+    let box x = Box::new('c'); //~ ERROR box pattern syntax is experimental in alpha release
+    println!("x: {}", x);
+}

src/test/compile-fail/issue-12116.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
+
 enum IntList {
     Cons(int, Box<IntList>),
     Nil

src/test/compile-fail/issue-14084.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
+
 fn main() {
     box ( () ) 0;
     //~^ ERROR: only the managed heap and exchange heap are currently supported

src/test/compile-fail/issue-3601.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
 
 struct HTMLImageData {
     image: Option<String>

src/test/compile-fail/issue-4972.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
 
 trait MyTrait { }
 

src/test/compile-fail/issue-5100.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
+
 enum A { B, C }
 
 fn main() {

src/test/compile-fail/moves-based-on-type-block-bad.rs

@@ -10,6 +10,8 @@
 
 // ignore-tidy-linelength
 
+#![feature(box_syntax)]
+
 struct S {
     x: Box<E>
 }

src/test/compile-fail/regions-ref-in-fn-arg.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(box_syntax)]
 
 fn arg_item(box ref x: Box<int>) -> &'static int {
     x //~^ ERROR borrowed value does not live long enough

src/test/compile-fail/unreachable-arm.rs

@@ -10,6 +10,7 @@
 
 // error-pattern:unreachable pattern
 
+#![feature(box_syntax)]
 
 enum foo { a(Box<foo>, int), b(uint), }
 

src/test/run-fail/args-panic.rs

@@ -11,6 +11,9 @@
 
 // error-pattern:meep
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn f(_a: int, _b: int, _c: Box<int>) { panic!("moop"); }
 
 fn main() { f(1, panic!("meep"), box 42); }

src/test/run-fail/panic-macro-any-wrapped.rs

@@ -10,6 +10,9 @@
 
 // error-pattern:panicked at 'Box<Any>'
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn main() {
     panic!(box 612_i64);
 }

src/test/run-fail/panic-macro-any.rs

@@ -10,6 +10,9 @@
 
 // error-pattern:panicked at 'Box<Any>'
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn main() {
     panic!(box 413i as Box<::std::any::Any+Send>);
 }

src/test/run-fail/unique-panic.rs

@@ -9,4 +9,8 @@
 // except according to those terms.
 
 // error-pattern: panic
+
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn main() { box panic!(); }

src/test/run-fail/unwind-unique.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 fn failfn() {
     panic!();

src/test/run-pass/alignment-gep-tup-like-1.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct pair<A,B> {
     a: A, b: B
 }

src/test/run-pass/assert-eq-macro-success.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 #[derive(PartialEq, Show)]
 struct Point { x : int }

src/test/run-pass/associated-type-doubleendediterator-object.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn pairwise_sub(mut t: Box<DoubleEndedIterator<Item=int>>) -> int {
     let mut result = 0;
     loop {

src/test/run-pass/autoderef-method-on-trait.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 trait double {
     fn double(self: Box<Self>) -> uint;

src/test/run-pass/autoderef-method-priority.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 trait double {
     fn double(self) -> uint;

src/test/run-pass/autoderef-method-twice-but-not-thrice.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 trait double {
     fn double(self: Box<Self>) -> uint;

src/test/run-pass/autoderef-method-twice.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 trait double {
     fn double(self: Box<Self>) -> uint;
 }

src/test/run-pass/autoderef-method.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 trait double {
     fn double(self: Box<Self>) -> uint;
 }

src/test/run-pass/autoref-intermediate-types-issue-3585.rs

@@ -9,6 +9,9 @@
 // except according to those terms.
 
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 trait Foo {
     fn foo(&self) -> String;
 }

src/test/run-pass/bitv-perf-test.rs

@@ -9,6 +9,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 extern crate collections;
 use std::collections::Bitv;
 

src/test/run-pass/borrowck-borrow-from-expr-block.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 fn borrow<F>(x: &int, f: F) where F: FnOnce(&int) {
     f(x)

src/test/run-pass/borrowck-field-sensitivity.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct A { a: int, b: Box<int> }
 struct B { a: Box<int>, b: Box<int> }
 

src/test/run-pass/borrowck-macro-interaction-issue-6304.rs

@@ -11,6 +11,7 @@
 // Check that we do not ICE when compiling this
 // macro, which reuses the expression `$id`
 
+#![feature(box_syntax)]
 
 struct Foo {
   a: int

src/test/run-pass/borrowck-move-by-capture-ok.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 #![feature(unboxed_closures)]
 
 pub fn main() {

src/test/run-pass/borrowck-mut-uniq.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::mem::swap;
 
 #[derive(Show)]

src/test/run-pass/borrowck-use-mut-borrow.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct A { a: int, b: Box<int> }
 
 fn field_copy_after_field_borrow() {

src/test/run-pass/cancel-clean-via-immediate-rvalue-ref.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 fn foo(x: &mut Box<u8>) {
     *x = box 5;

src/test/run-pass/capturing-logging.rs

@@ -11,6 +11,9 @@
 // ignore-android (FIXME #11419)
 // exec-env:RUST_LOG=info
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 #[macro_use]
 extern crate log;
 

src/test/run-pass/cci_borrow.rs

@@ -10,6 +10,8 @@
 
 // aux-build:cci_borrow_lib.rs
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 extern crate cci_borrow_lib;
 use cci_borrow_lib::foo;

src/test/run-pass/class-cast-to-trait-cross-crate-2.rs

@@ -9,6 +9,10 @@
 // except according to those terms.
 
 // aux-build:cci_class_cast.rs
+
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 extern crate cci_class_cast;
 
 use std::string::ToString;

src/test/run-pass/class-separate-impl.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::fmt;
 
 struct cat {

src/test/run-pass/cleanup-arm-conditional.rs

@@ -21,6 +21,9 @@
 // Test that cleanup scope for temporaries created in a match
 // arm is confined to the match arm itself.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::os;
 
 struct Test { x: int }

src/test/run-pass/cleanup-rvalue-during-if-and-while.rs

@@ -12,6 +12,8 @@
 // This test verifies that temporaries created for `while`'s and `if`
 // conditions are dropped after the condition is evaluated.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 struct Temporary;
 

src/test/run-pass/cleanup-rvalue-scopes.rs

@@ -12,6 +12,8 @@
 // statement or end of block, as appropriate given the temporary
 // lifetime rules.
 
+#![feature(box_syntax)]
+
 use std::ops::Drop;
 
 static mut FLAGS: u64 = 0;

src/test/run-pass/cleanup-rvalue-temp-during-incomplete-alloc.rs

@@ -24,6 +24,9 @@
 // It's unclear how likely such a bug is to recur, but it seems like a
 // scenario worth testing.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::thread::Thread;
 
 enum Conzabble {

src/test/run-pass/clone-with-exterior.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::thread::Thread;
 
 struct Pair {

src/test/run-pass/close-over-big-then-small-data.rs

@@ -12,6 +12,9 @@
 // storing closure data (as we used to do), the u64 would
 // overwrite the u16.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct Pair<A,B> {
     a: A, b: B
 }

src/test/run-pass/coerce-expect-unsized.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::fmt::Show;
 
 // Check that coercions apply at the pointer level and don't cause

src/test/run-pass/coerce-match-calls.rs

@@ -0,0 +1,23 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <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.
+
+// Check that coercions are propagated through match and if expressions.
+
+use std::boxed::Box;
+
+pub fn main() {
+    let _: Box<[int]> = if true { Box::new([1i, 2, 3]) } else { Box::new([1i]) };
+
+    let _: Box<[int]> = match true { true => Box::new([1i, 2, 3]), false => Box::new([1i]) };
+
+    // Check we don't get over-keen at propagating coercions in the case of casts.
+    let x = if true { 42 } else { 42u8 } as u16;
+    let x = match true { true => 42, false => 42u8 } as u16;
+}

src/test/run-pass/coerce-match.rs

@@ -10,6 +10,9 @@
 
 // Check that coercions are propagated through match and if expressions.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 pub fn main() {
     let _: Box<[int]> = if true { box [1i, 2, 3] } else { box [1i] };
 

src/test/run-pass/const-bound.rs

@@ -11,6 +11,8 @@
 // Make sure const bounds work on things, and test that a few types
 // are const.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 fn foo<T: Sync>(x: T) -> T { x }
 

src/test/run-pass/crate-method-reexport-grrrrrrr.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 // This is a regression test that the metadata for the
 // name_pool::methods impl in the other crate is reachable from this

src/test/run-pass/deref-lval.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 use std::cell::Cell;
 

src/test/run-pass/deref.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 pub fn main() {
     let x: Box<int> = box 10;

src/test/run-pass/deriving-default-box.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::default::Default;
 
 #[derive(Default)]

src/test/run-pass/deriving-encodable-decodable-box.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 #![feature(old_orphan_check)]
 
 extern crate serialize;

src/test/run-pass/deriving-eq-ord-boxed-slice.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 #[derive(PartialEq, PartialOrd, Eq, Ord)]
 struct Foo(Box<[u8]>);
 

src/test/run-pass/drop-on-empty-block-exit.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 enum t { foo(Box<int>), }
 

src/test/run-pass/drop-struct-as-object.rs

@@ -11,6 +11,9 @@
 // Test that destructor on a struct runs successfully after the struct
 // is boxed and converted to an object.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 static mut value: uint = 0;
 
 struct Cat {

src/test/run-pass/drop-trait-enum.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::thread::Thread;
 use std::sync::mpsc::{channel, Sender};
 

src/test/run-pass/dst-deref-mut.rs

@@ -10,6 +10,9 @@
 
 // Test that a custom deref with a fat pointer return type does not ICE
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::ops::{Deref, DerefMut};
 
 pub struct Arr {

src/test/run-pass/dst-deref.rs

@@ -10,6 +10,9 @@
 
 // Test that a custom deref with a fat pointer return type does not ICE
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 use std::ops::Deref;
 
 pub struct Arr {

src/test/run-pass/dst-struct.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct Fat<T: ?Sized> {
     f1: int,
     f2: &'static str,

src/test/run-pass/dst-trait.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct Fat<T: ?Sized> {
     f1: int,
     f2: &'static str,

src/test/run-pass/empty-allocation-non-null.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 pub fn main() {
     assert!(Some(box() ()).is_some());
 

src/test/run-pass/empty-allocation-rvalue-non-null.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 pub fn main() {
     let x = *box() ();
 }

src/test/run-pass/enum-nullable-simplifycfg-misopt.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 /*!
  * This is a regression test for a bug in LLVM, fixed in upstream r179587,

src/test/run-pass/explicit-self-generic.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 struct LM { resize_at: uint, size: uint }
 
 impl Copy for LM {}

src/test/run-pass/explicit-self-objects-uniq.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 trait Foo {
     fn f(self: Box<Self>);

src/test/run-pass/explicit-self.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 static tau: f64 = 2.0*3.14159265358979323;
 
 struct Point {x: f64, y: f64}

src/test/run-pass/expr-block-generic-unique1.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn test_generic<T, F>(expected: Box<T>, eq: F) where T: Clone, F: FnOnce(Box<T>, Box<T>) -> bool {
     let actual: Box<T> = { expected.clone() };
     assert!(eq(expected, actual));

src/test/run-pass/expr-block-generic-unique2.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn test_generic<T, F>(expected: T, eq: F) where T: Clone, F: FnOnce(T, T) -> bool {
     let actual: T = { expected.clone() };
     assert!(eq(expected, actual));

src/test/run-pass/expr-block-unique.rs

@@ -9,6 +9,7 @@
 // except according to those terms.
 
 
-
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 pub fn main() { let x = { box 100i }; assert!((*x == 100)); }

src/test/run-pass/expr-if-unique.rs

@@ -9,7 +9,8 @@
 // except according to those terms.
 
 
-
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 
 // Tests for if as expressions returning boxed types

src/test/run-pass/expr-match-generic-unique1.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn test_generic<T: Clone, F>(expected: Box<T>, eq: F) where F: FnOnce(Box<T>, Box<T>) -> bool {
     let actual: Box<T> = match true {
         true => { expected.clone() },

src/test/run-pass/expr-match-generic-unique2.rs

@@ -8,6 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
+
 fn test_generic<T: Clone, F>(expected: T, eq: F) where F: FnOnce(T, T) -> bool {
     let actual: T = match true {
         true => expected.clone(),

src/test/run-pass/expr-match-unique.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![allow(unknown_features)]
+#![feature(box_syntax)]
 
 // Tests for match as expressions resulting in boxed types
 fn test_box() {