diff --git a/src/libextra/bitv.rs b/src/libextra/bitv.rs
index 44e5ca56c43..85002029fc6 100644
--- a/src/libextra/bitv.rs
+++ b/src/libextra/bitv.rs
@@ -717,6 +717,41 @@ impl BitvSet {
     pub fn iter<'a>(&'a self) -> BitvSetIterator<'a> {
         BitvSetIterator {set: self, next_idx: 0}
     }
+
+    pub fn difference(&self, other: &BitvSet, f: &fn(&uint) -> bool) -> bool {
+        for self.common_iter(other).advance |(i, w1, w2)| {
+            if !iterate_bits(i, w1 & !w2, |b| f(&b)) {
+                return false;
+            }
+        }
+        /* everything we have that they don't also shows up */
+        self.outlier_iter(other).advance(|(mine, i, w)|
+            !mine || iterate_bits(i, w, |b| f(&b))
+        )
+    }
+
+    pub fn symmetric_difference(&self, other: &BitvSet,
+                            f: &fn(&uint) -> bool) -> bool {
+        for self.common_iter(other).advance |(i, w1, w2)| {
+            if !iterate_bits(i, w1 ^ w2, |b| f(&b)) {
+                return false;
+            }
+        }
+        self.outlier_iter(other).advance(|(_, i, w)| iterate_bits(i, w, |b| f(&b)))
+    }
+
+    pub fn intersection(&self, other: &BitvSet, f: &fn(&uint) -> bool) -> bool {
+        self.common_iter(other).advance(|(i, w1, w2)| iterate_bits(i, w1 & w2, |b| f(&b)))
+    }
+
+    pub fn union(&self, other: &BitvSet, f: &fn(&uint) -> bool) -> bool {
+        for self.common_iter(other).advance |(i, w1, w2)| {
+            if !iterate_bits(i, w1 | w2, |b| f(&b)) {
+                return false;
+            }
+        }
+        self.outlier_iter(other).advance(|(_, i, w)| iterate_bits(i, w, |b| f(&b)))
+    }
 }
 
 impl cmp::Eq for BitvSet {
@@ -785,41 +820,6 @@ impl Set<uint> for BitvSet {
     fn is_superset(&self, other: &BitvSet) -> bool {
         other.is_subset(self)
     }
-
-    fn difference(&self, other: &BitvSet, f: &fn(&uint) -> bool) -> bool {
-        for self.common_iter(other).advance |(i, w1, w2)| {
-            if !iterate_bits(i, w1 & !w2, |b| f(&b)) {
-                return false;
-            }
-        }
-        /* everything we have that they don't also shows up */
-        self.outlier_iter(other).advance(|(mine, i, w)|
-            !mine || iterate_bits(i, w, |b| f(&b))
-        )
-    }
-
-    fn symmetric_difference(&self, other: &BitvSet,
-                            f: &fn(&uint) -> bool) -> bool {
-        for self.common_iter(other).advance |(i, w1, w2)| {
-            if !iterate_bits(i, w1 ^ w2, |b| f(&b)) {
-                return false;
-            }
-        }
-        self.outlier_iter(other).advance(|(_, i, w)| iterate_bits(i, w, |b| f(&b)))
-    }
-
-    fn intersection(&self, other: &BitvSet, f: &fn(&uint) -> bool) -> bool {
-        self.common_iter(other).advance(|(i, w1, w2)| iterate_bits(i, w1 & w2, |b| f(&b)))
-    }
-
-    fn union(&self, other: &BitvSet, f: &fn(&uint) -> bool) -> bool {
-        for self.common_iter(other).advance |(i, w1, w2)| {
-            if !iterate_bits(i, w1 | w2, |b| f(&b)) {
-                return false;
-            }
-        }
-        self.outlier_iter(other).advance(|(_, i, w)| iterate_bits(i, w, |b| f(&b)))
-    }
 }
 
 impl MutableSet<uint> for BitvSet {
diff --git a/src/libextra/treemap.rs b/src/libextra/treemap.rs
index 4e66870a947..8a2d6cfcf49 100644
--- a/src/libextra/treemap.rs
+++ b/src/libextra/treemap.rs
@@ -396,9 +396,40 @@ impl<T: TotalOrd> Set<T> for TreeSet<T> {
         }
         true
     }
+}
+
+impl<T: TotalOrd> MutableSet<T> for TreeSet<T> {
+    /// Add a value to the set. Return true if the value was not already
+    /// present in the set.
+    #[inline]
+    fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) }
+
+    /// Remove a value from the set. Return true if the value was
+    /// present in the set.
+    #[inline]
+    fn remove(&mut self, value: &T) -> bool { self.map.remove(value) }
+}
+
+impl<T: TotalOrd> TreeSet<T> {
+    /// Create an empty TreeSet
+    #[inline]
+    pub fn new() -> TreeSet<T> { TreeSet{map: TreeMap::new()} }
+
+    /// Get a lazy iterator over the values in the set.
+    /// Requires that it be frozen (immutable).
+    #[inline]
+    pub fn iter<'a>(&'a self) -> TreeSetIterator<'a, T> {
+        TreeSetIterator{iter: self.map.iter()}
+    }
+
+    /// Visit all values in reverse order
+    #[inline]
+    pub fn each_reverse(&self, f: &fn(&T) -> bool) -> bool {
+        self.map.each_key_reverse(f)
+    }
 
     /// Visit the values (in-order) representing the difference
-    fn difference(&self, other: &TreeSet<T>, f: &fn(&T) -> bool) -> bool {
+    pub fn difference(&self, other: &TreeSet<T>, f: &fn(&T) -> bool) -> bool {
         let mut x = self.iter();
         let mut y = other.iter();
 
@@ -427,7 +458,7 @@ impl<T: TotalOrd> Set<T> for TreeSet<T> {
     }
 
     /// Visit the values (in-order) representing the symmetric difference
-    fn symmetric_difference(&self, other: &TreeSet<T>,
+    pub fn symmetric_difference(&self, other: &TreeSet<T>,
                             f: &fn(&T) -> bool) -> bool {
         let mut x = self.iter();
         let mut y = other.iter();
@@ -461,7 +492,7 @@ impl<T: TotalOrd> Set<T> for TreeSet<T> {
     }
 
     /// Visit the values (in-order) representing the intersection
-    fn intersection(&self, other: &TreeSet<T>, f: &fn(&T) -> bool) -> bool {
+    pub fn intersection(&self, other: &TreeSet<T>, f: &fn(&T) -> bool) -> bool {
         let mut x = self.iter();
         let mut y = other.iter();
 
@@ -487,7 +518,7 @@ impl<T: TotalOrd> Set<T> for TreeSet<T> {
     }
 
     /// Visit the values (in-order) representing the union
-    fn union(&self, other: &TreeSet<T>, f: &fn(&T) -> bool) -> bool {
+    pub fn union(&self, other: &TreeSet<T>, f: &fn(&T) -> bool) -> bool {
         let mut x = self.iter();
         let mut y = other.iter();
 
@@ -519,37 +550,6 @@ impl<T: TotalOrd> Set<T> for TreeSet<T> {
     }
 }
 
-impl<T: TotalOrd> MutableSet<T> for TreeSet<T> {
-    /// Add a value to the set. Return true if the value was not already
-    /// present in the set.
-    #[inline]
-    fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) }
-
-    /// Remove a value from the set. Return true if the value was
-    /// present in the set.
-    #[inline]
-    fn remove(&mut self, value: &T) -> bool { self.map.remove(value) }
-}
-
-impl<T: TotalOrd> TreeSet<T> {
-    /// Create an empty TreeSet
-    #[inline]
-    pub fn new() -> TreeSet<T> { TreeSet{map: TreeMap::new()} }
-
-    /// Get a lazy iterator over the values in the set.
-    /// Requires that it be frozen (immutable).
-    #[inline]
-    pub fn iter<'a>(&'a self) -> TreeSetIterator<'a, T> {
-        TreeSetIterator{iter: self.map.iter()}
-    }
-
-    /// Visit all values in reverse order
-    #[inline]
-    pub fn each_reverse(&self, f: &fn(&T) -> bool) -> bool {
-        self.map.each_key_reverse(f)
-    }
-}
-
 /// Lazy forward iterator over a set
 pub struct TreeSetIterator<'self, T> {
     priv iter: TreeMapIterator<'self, T, ()>
diff --git a/src/libstd/container.rs b/src/libstd/container.rs
index d855beea50b..10f3fc6586f 100644
--- a/src/libstd/container.rs
+++ b/src/libstd/container.rs
@@ -87,17 +87,7 @@ pub trait Set<T>: Container {
     /// Return true if the set is a superset of another
     fn is_superset(&self, other: &Self) -> bool;
 
-    /// Visit the values representing the difference
-    fn difference(&self, other: &Self, f: &fn(&T) -> bool) -> bool;
-
-    /// Visit the values representing the symmetric difference
-    fn symmetric_difference(&self, other: &Self, f: &fn(&T) -> bool) -> bool;
-
-    /// Visit the values representing the intersection
-    fn intersection(&self, other: &Self, f: &fn(&T) -> bool) -> bool;
-
-    /// Visit the values representing the union
-    fn union(&self, other: &Self, f: &fn(&T) -> bool) -> bool;
+    // FIXME #8154: Add difference, sym. difference, intersection and union iterators
 }
 
 /// This trait represents actions which can be performed on sets to mutate
diff --git a/src/libstd/hashmap.rs b/src/libstd/hashmap.rs
index 8c06f23b8c1..ca61f3e5ad8 100644
--- a/src/libstd/hashmap.rs
+++ b/src/libstd/hashmap.rs
@@ -672,28 +672,6 @@ impl<T:Hash + Eq> Set<T> for HashSet<T> {
     fn is_superset(&self, other: &HashSet<T>) -> bool {
         other.is_subset(self)
     }
-
-    /// Visit the values representing the difference
-    fn difference(&self, other: &HashSet<T>, f: &fn(&T) -> bool) -> bool {
-        self.difference_iter(other).advance(f)
-    }
-
-    /// Visit the values representing the symmetric difference
-    fn symmetric_difference(&self,
-                            other: &HashSet<T>,
-                            f: &fn(&T) -> bool) -> bool {
-        self.symmetric_difference_iter(other).advance(f)
-    }
-
-    /// Visit the values representing the intersection
-    fn intersection(&self, other: &HashSet<T>, f: &fn(&T) -> bool) -> bool {
-        self.intersection_iter(other).advance(f)
-    }
-
-    /// Visit the values representing the union
-    fn union(&self, other: &HashSet<T>, f: &fn(&T) -> bool) -> bool {
-        self.union_iter(other).advance(f)
-    }
 }
 
 impl<T:Hash + Eq> MutableSet<T> for HashSet<T> {