Generalise RootedVec::<JS<T>>::r as [JS<T>]::r

components/script/dom/bindings/js.rs

@@ -456,6 +456,13 @@ pub trait RootedReference<'root> {
     fn r(&'root self) -> Self::Ref;
 }
 
+impl<'root, T: JSTraceable + Reflectable + 'root> RootedReference<'root> for [JS<T>] {
+    type Ref = &'root [&'root T];
+    fn r(&'root self) -> &'root [&'root T] {
+        unsafe { mem::transmute(self) }
+    }
+}
+
 impl<'root, T: RootedReference<'root> + 'root> RootedReference<'root> for Option<T> {
     type Ref = Option<T::Ref>;
     fn r(&'root self) -> Option<T::Ref> {

components/script/dom/bindings/trace.rs

@@ -34,7 +34,7 @@ use canvas_traits::{CompositionOrBlending, LineCapStyle, LineJoinStyle, Repetiti
 use cssparser::RGBA;
 use devtools_traits::CSSError;
 use devtools_traits::WorkerId;
-use dom::bindings::js::{JS, Root, RootedReference};
+use dom::bindings::js::{JS, Root};
 use dom::bindings::refcounted::Trusted;
 use dom::bindings::reflector::{Reflectable, Reflector};
 use dom::bindings::utils::WindowProxyHandler;
@@ -75,7 +75,6 @@ use std::collections::{BTreeMap, HashMap, HashSet};
 use std::hash::{BuildHasher, Hash};
 use std::intrinsics::return_address;
 use std::iter::{FromIterator, IntoIterator};
-use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::rc::Rc;
 use std::sync::Arc;
@@ -509,13 +508,6 @@ impl<T: JSTraceable> RootedVec<T> {
     }
 }
 
-impl<'root, T: JSTraceable + Reflectable + 'root> RootedReference<'root> for RootedVec<JS<T>> {
-    type Ref = &'root [&'root T];
-    fn r(&'root self) -> &'root [&'root T] {
-        unsafe { mem::transmute(&self.v[..]) }
-    }
-}
-
 impl<T: JSTraceable> Drop for RootedVec<T> {
     fn drop(&mut self) {
         unsafe {