add leaves

Change-Id: I962bb4e74f39ec0a838f984b8c13a420ba36d7ce
diff --git a/src/interpreter.hpp b/src/interpreter.hpp
index a4a5cc0..64cc0e9 100644
--- a/src/interpreter.hpp
+++ b/src/interpreter.hpp
@@ -14,6 +14,7 @@
 struct Interpreter : boost::static_visitor<void> {
     Interpreter(Parser& parser, Schema&);
 
+    void operator()(const set_&) const;
     void operator()(const cd_&) const;
     void operator()(const create_&) const;
     void operator()(const delete_&) const;