--- a/src/types.rs	Sat Jun 11 13:19:42 2016 +0200
+++ b/src/types.rs	Sat Jun 11 13:21:15 2016 +0200
@@ -87,6 +87,11 @@
         }
         self.map.remove(&ss);
     }
+
+    pub fn empty(&self) -> bool {
+        self.oldest == 0
+    }
+
 }
 
 #[cfg(test)]
@@ -97,10 +102,14 @@
     fn test_snapshot_list() {
         let mut l = SnapshotList::new();
 
+        assert!(l.empty());
+
         let oldest = l.new_snapshot(1);
         l.new_snapshot(2);
         let newest = l.new_snapshot(0);
 
+        assert!(!l.empty());
+
         assert_eq!(l.oldest(), 1);
         assert_eq!(l.newest(), 0);