From 13812492650e9530bc940f944fda7c55b485b32d Mon Sep 17 00:00:00 2001
From: Andrew Paseltiner <apaseltiner@gmail.com>
Date: Sat, 21 Mar 2015 22:55:52 -0400
Subject: [PATCH] implement `Clone` for `btree` iterators

---
 src/libcollections/btree/map.rs  | 13 +++++++++++++
 src/libcollections/btree/node.rs |  2 ++
 src/libcollections/btree/set.rs  | 26 ++++++++++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index c7e1e3c91766..b0ec559113b5 100644
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -78,6 +78,7 @@ pub struct BTreeMap<K, V> {
 }
 
 /// An abstract base over-which all other BTree iterators are built.
+#[derive(Clone)]
 struct AbsIter<T> {
     traversals: VecDeque<T>,
     size: usize,
@@ -1034,6 +1035,9 @@ impl<K, V, E, T> DoubleEndedIterator for AbsIter<T> where
     }
 }
 
+impl<'a, K, V> Clone for Iter<'a, K, V> {
+    fn clone(&self) -> Iter<'a, K, V> { Iter { inner: self.inner.clone() } }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, K, V> Iterator for Iter<'a, K, V> {
     type Item = (&'a K, &'a V);
@@ -1076,6 +1080,9 @@ impl<K, V> DoubleEndedIterator for IntoIter<K, V> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<K, V> ExactSizeIterator for IntoIter<K, V> {}
 
+impl<'a, K, V> Clone for Keys<'a, K, V> {
+    fn clone(&self) -> Keys<'a, K, V> { Keys { inner: self.inner.clone() } }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, K, V> Iterator for Keys<'a, K, V> {
     type Item = &'a K;
@@ -1091,6 +1098,9 @@ impl<'a, K, V> DoubleEndedIterator for Keys<'a, K, V> {
 impl<'a, K, V> ExactSizeIterator for Keys<'a, K, V> {}
 
 
+impl<'a, K, V> Clone for Values<'a, K, V> {
+    fn clone(&self) -> Values<'a, K, V> { Values { inner: self.inner.clone() } }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, K, V> Iterator for Values<'a, K, V> {
     type Item = &'a V;
@@ -1105,6 +1115,9 @@ impl<'a, K, V> DoubleEndedIterator for Values<'a, K, V> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, K, V> ExactSizeIterator for Values<'a, K, V> {}
 
+impl<'a, K, V> Clone for Range<'a, K, V> {
+    fn clone(&self) -> Range<'a, K, V> { Range { inner: self.inner.clone() } }
+}
 impl<'a, K, V> Iterator for Range<'a, K, V> {
     type Item = (&'a K, &'a V);
 
diff --git a/src/libcollections/btree/node.rs b/src/libcollections/btree/node.rs
index bfac3b2df5a5..0af83280a41c 100644
--- a/src/libcollections/btree/node.rs
+++ b/src/libcollections/btree/node.rs
@@ -1326,6 +1326,7 @@ trait TraversalImpl {
 
 /// A `TraversalImpl` that actually is backed by two iterators. This works in the non-moving case,
 /// as no deallocation needs to be done.
+#[derive(Clone)]
 struct ElemsAndEdges<Elems, Edges>(Elems, Edges);
 
 impl<K, V, E, Elems: DoubleEndedIterator, Edges: DoubleEndedIterator>
@@ -1404,6 +1405,7 @@ impl<K, V> Drop for MoveTraversalImpl<K, V> {
 }
 
 /// An abstraction over all the different kinds of traversals a node supports
+#[derive(Clone)]
 struct AbsTraversal<Impl> {
     inner: Impl,
     head_is_edge: bool,
diff --git a/src/libcollections/btree/set.rs b/src/libcollections/btree/set.rs
index 5616d36ce0ba..c0e4a32eee09 100644
--- a/src/libcollections/btree/set.rs
+++ b/src/libcollections/btree/set.rs
@@ -628,6 +628,9 @@ impl<T: Debug> Debug for BTreeSet<T> {
     }
 }
 
+impl<'a, T> Clone for Iter<'a, T> {
+    fn clone(&self) -> Iter<'a, T> { Iter { iter: self.iter.clone() } }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> Iterator for Iter<'a, T> {
     type Item = &'a T;
@@ -658,6 +661,9 @@ impl<T> DoubleEndedIterator for IntoIter<T> {
 impl<T> ExactSizeIterator for IntoIter<T> {}
 
 
+impl<'a, T> Clone for Range<'a, T> {
+    fn clone(&self) -> Range<'a, T> { Range { iter: self.iter.clone() } }
+}
 impl<'a, T> Iterator for Range<'a, T> {
     type Item = &'a T;
 
@@ -677,6 +683,11 @@ fn cmp_opt<T: Ord>(x: Option<&T>, y: Option<&T>,
     }
 }
 
+impl<'a, T> Clone for Difference<'a, T> {
+    fn clone(&self) -> Difference<'a, T> {
+        Difference { a: self.a.clone(), b: self.b.clone() }
+    }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: Ord> Iterator for Difference<'a, T> {
     type Item = &'a T;
@@ -692,6 +703,11 @@ impl<'a, T: Ord> Iterator for Difference<'a, T> {
     }
 }
 
+impl<'a, T> Clone for SymmetricDifference<'a, T> {
+    fn clone(&self) -> SymmetricDifference<'a, T> {
+        SymmetricDifference { a: self.a.clone(), b: self.b.clone() }
+    }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> {
     type Item = &'a T;
@@ -707,6 +723,11 @@ impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> {
     }
 }
 
+impl<'a, T> Clone for Intersection<'a, T> {
+    fn clone(&self) -> Intersection<'a, T> {
+        Intersection { a: self.a.clone(), b: self.b.clone() }
+    }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: Ord> Iterator for Intersection<'a, T> {
     type Item = &'a T;
@@ -728,6 +749,11 @@ impl<'a, T: Ord> Iterator for Intersection<'a, T> {
     }
 }
 
+impl<'a, T> Clone for Union<'a, T> {
+    fn clone(&self) -> Union<'a, T> {
+        Union { a: self.a.clone(), b: self.b.clone() }
+    }
+}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: Ord> Iterator for Union<'a, T> {
     type Item = &'a T;