add assert to get_first_token

diff --git a/src/storage/phrase_large_table2.h b/src/storage/phrase_large_table2.h
index c4d4092..9f9f718 100644 (file)
--- a/src/storage/phrase_large_table2.h
+++ b/src/storage/phrase_large_table2.h
@@ -125,6 +125,9 @@ static inline int get_first_token(PhraseTokens tokens,
         }
     }
 
+    /* the following line will be removed in future after code are verified. */
+    assert(0 == num || 1 == num);
+
     return num;
 }