Adding a unit test using boost Unit Test Framework
diff --git a/model/sync-digest.h b/model/sync-digest.h
index f5c83f6..91b331e 100644
--- a/model/sync-digest.h
+++ b/model/sync-digest.h
@@ -42,6 +42,12 @@
Digest ();
/**
+ * @brief Check if digest is empty
+ */
+ bool
+ empty () const;
+
+ /**
* @brief Reset digest to the initial state
*/
void
@@ -66,7 +72,12 @@
* Side effect: Finalize will be called on `this' and `digest'
*/
bool
- operator == (Digest &digest);
+ operator == (const Digest &digest) const;
+
+ bool
+ operator != (const Digest &digest) const
+ { return ! (*this == digest); }
+
/**
* @brief Add existing digest to digest calculation