diff --git a/src/components/util/smallvec.rs b/src/components/util/smallvec.rs
index ab51fd961f1..614d211ea3a 100644
--- a/src/components/util/smallvec.rs
+++ b/src/components/util/smallvec.rs
@@ -60,6 +60,12 @@ pub trait SmallVec<T> : SmallVecPrivate<T> {
         }
     }
 
+    fn mut_iter<'a>(&'a mut self) -> SmallVecMutIterator<'a,T> {
+        SmallVecMutIterator {
+            iter: self.iter(),
+        }
+    }
+
     /// NB: For efficiency reasons (avoiding making a second copy of the inline elements), this
     /// actually clears out the original array instead of moving it.
     fn move_iter<'a>(&'a mut self) -> SmallVecMoveIterator<'a,T> {
@@ -94,6 +100,12 @@ pub trait SmallVec<T> : SmallVecPrivate<T> {
         }
     }
 
+    fn push_all_move<V:SmallVec<T>>(&mut self, mut other: V) {
+        for value in other.move_iter() {
+            self.push(value)
+        }
+    }
+
     fn grow(&mut self, new_cap: uint) {
         unsafe {
             let new_alloc: *mut T = cast::transmute(global_heap::malloc_raw(mem::size_of::<T>() *
@@ -194,6 +206,22 @@ impl<'a,T> Iterator<&'a T> for SmallVecIterator<'a,T> {
     }
 }
 
+pub struct SmallVecMutIterator<'a,T> {
+    priv iter: SmallVecIterator<'a,T>,
+}
+
+impl<'a,T> Iterator<&'a mut T> for SmallVecMutIterator<'a,T> {
+    #[inline]
+    fn next(&mut self) -> Option<&'a mut T> {
+        unsafe {
+            match self.iter.next() {
+                None => None,
+                Some(reference) => Some(cast::transmute::<&'a T,&'a mut T>(reference)),
+            }
+        }
+    }
+}
+
 pub struct SmallVecMoveIterator<'a,T> {
     priv allocation: Option<*mut u8>,
     priv iter: SmallVecIterator<'static,T>,