Index: src/SynTree/Label.h
===================================================================
--- src/SynTree/Label.h	(revision 8aa474a522cf439767cfb0cb3720af96323fc04f)
+++ src/SynTree/Label.h	(revision 94e025a2958da9396d8ffadfcf0855fdbe053025)
@@ -33,5 +33,5 @@
 	std::list< Attribute * >& get_attributes() { return attributes; }
 
-	operator std::string() { return name; }
+	operator std::string() const { return name; }
 	bool empty() { return name.empty(); }
   private: