Value::compare() is now const and has an actual implementation with unit tests.
diff --git a/include/json/value.h b/include/json/value.h
index b629d8c..c9c7e1d 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -256,7 +256,7 @@
       bool operator ==( const Value &other ) const;
       bool operator !=( const Value &other ) const;
 
-      int compare( const Value &other );
+      int compare( const Value &other ) const;
 
       const char *asCString() const;
       std::string asString() const;