1 files changed, 1 insertions, 1 deletions
diff --git a/decoder/trule.h b/decoder/trule.h
index 04058a41..e73fd0fe 100644
--- a/decoder/trule.h
+++ b/decoder/trule.h
@@ -104,7 +104,7 @@ class TRule {
   bool Initialized() const { return e_.size(); }
 
   std::string AsString(bool verbose = true) const;
-
+  friend std::ostream &operator<<(std::ostream &o,TRule const& r);
   static TRule DummyRule() {
     TRule res;
     res.e_.resize(1, 0);