1 files changed, 10 insertions, 0 deletions
diff --git a/src/hash.cc b/src/hash.cc
index 72dcd790c7dc..97bf8f7856f0 100644
--- a/src/hash.cc
+++ b/src/hash.cc
@@ -28,6 +28,16 @@ bool Hash::operator != (Hash h2)
 }
 
 
+bool Hash::operator < (const Hash & h) const
+{
+    for (unsigned int i = 0; i < hashSize; i++) {
+        if (hash[i] < h.hash[i]) return true;
+        if (hash[i] > h.hash[i]) return false;
+    }
+    return false;
+}
+
+
 Hash::operator string() const
 {
     ostringstream str;