DSTify Box<T> implementation of PartialEq, PartialOrd, Eq, Ord

Author: Jorge Aparicio

src/liballoc/boxed.rs

@@ -61,12 +61,16 @@ impl<T: Clone> Clone for Box<T> {
     }
 }
 
+// NOTE(stage0): remove impl after a snapshot
+#[cfg(stage0)]
 impl<T:PartialEq> PartialEq for Box<T> {
     #[inline]
     fn eq(&self, other: &Box<T>) -> bool { *(*self) == *(*other) }
     #[inline]
     fn ne(&self, other: &Box<T>) -> bool { *(*self) != *(*other) }
 }
+// NOTE(stage0): remove impl after a snapshot
+#[cfg(stage0)]
 impl<T:PartialOrd> PartialOrd for Box<T> {
     #[inline]
     fn partial_cmp(&self, other: &Box<T>) -> Option<Ordering> {
@@ -81,14 +85,50 @@ impl<T:PartialOrd> PartialOrd for Box<T> {
     #[inline]
     fn gt(&self, other: &Box<T>) -> bool { *(*self) > *(*other) }
 }
+// NOTE(stage0): remove impl after a snapshot
+#[cfg(stage0)]
 impl<T: Ord> Ord for Box<T> {
     #[inline]
     fn cmp(&self, other: &Box<T>) -> Ordering {
         (**self).cmp(&**other)
     }
 }
+// NOTE(stage0): remove impl after a snapshot
+#[cfg(stage0)]
 impl<T: Eq> Eq for Box<T> {}
 
+#[cfg(not(stage0))]  // NOTE(stage0): remove cfg after a snapshot
+impl<Sized? T: PartialEq> PartialEq for Box<T> {
+    #[inline]
+    fn eq(&self, other: &Box<T>) -> bool { PartialEq::eq(&**self, &**other) }
+    #[inline]
+    fn ne(&self, other: &Box<T>) -> bool { PartialEq::ne(&**self, &**other) }
+}
+#[cfg(not(stage0))]  // NOTE(stage0): remove cfg after a snapshot
+impl<Sized? T: PartialOrd> PartialOrd for Box<T> {
+    #[inline]
+    fn partial_cmp(&self, other: &Box<T>) -> Option<Ordering> {
+        PartialOrd::partial_cmp(&**self, &**other)
+    }
+    #[inline]
+    fn lt(&self, other: &Box<T>) -> bool { PartialOrd::lt(&**self, &**other) }
+    #[inline]
+    fn le(&self, other: &Box<T>) -> bool { PartialOrd::le(&**self, &**other) }
+    #[inline]
+    fn ge(&self, other: &Box<T>) -> bool { PartialOrd::ge(&**self, &**other) }
+    #[inline]
+    fn gt(&self, other: &Box<T>) -> bool { PartialOrd::gt(&**self, &**other) }
+}
+#[cfg(not(stage0))]  // NOTE(stage0): remove cfg after a snapshot
+impl<Sized? T: Ord> Ord for Box<T> {
+    #[inline]
+    fn cmp(&self, other: &Box<T>) -> Ordering {
+        Ord::cmp(&**self, &**other)
+    }
+}
+#[cfg(not(stage0))]  // NOTE(stage0): remove cfg after a snapshot
+impl<Sized? T: Eq> Eq for Box<T> {}
+
 /// Extension methods for an owning `Any` trait object.
 #[unstable = "post-DST and coherence changes, this will not be a trait but \
               rather a direct `impl` on `Box<Any>`"]

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

@@ -0,0 +1,24 @@
+// Copyright 2012 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.
+
+#[deriving(PartialEq, PartialOrd, Eq, Ord)]
+struct Foo(Box<[u8]>);
+
+pub fn main() {
+    let a = Foo(box [0, 1, 2]);
+    let b = Foo(box [0, 1, 2]);
+    assert!(a == b);
+    println!("{}", a != b);
+    println!("{}", a < b);
+    println!("{}", a <= b);
+    println!("{}", a == b);
+    println!("{}", a > b);
+    println!("{}", a >= b);
+}