1 files changed, 18 insertions, 2 deletions
diff --git a/src/mongo/s/catalog/type_chunk.h b/src/mongo/s/catalog/type_chunk.h
index 9827b5a3a79..96ee1588a6a 100644
--- a/src/mongo/s/catalog/type_chunk.h
+++ b/src/mongo/s/catalog/type_chunk.h
@@ -83,9 +83,25 @@ public:
     bool operator==(const ChunkRange& other) const;
     bool operator!=(const ChunkRange& other) const;
 
+    /**
+     * Returns true iff the union of *this and the argument range is the same as *this.
+     */
+    bool covers(ChunkRange const& other) const;
+
+    /**
+     * Returns the range of overlap between *this and other, if any.
+     */
+    boost::optional<ChunkRange> overlapWith(ChunkRange const& other) const;
+
+    /**
+     * Returns a range that includes *this and other. If the ranges do not overlap, it includes
+     * all the space between, as well.
+     */
+    ChunkRange unionWith(ChunkRange const& other) const;
+
 private:
-    BSONObj _minKey;
-    BSONObj _maxKey;
+    const BSONObj _minKey;
+    const BSONObj _maxKey;
 };
 
 /**