fix: enum directive_type UNDEF and DEFINE should be different

saifeiLee · saifeiLee · commit 290e46b1b9ce · 2022-06-30T17:22:04.000+08:00
diff --git a/chapter_6/exercise_6_06/define.c b/chapter_6/exercise_6_06/define.c
@@ -17,7 +17,7 @@ enum directive_type
 {
   NONE = 0,
   DEFINE = 1,
-  UNDEF = 1
+  UNDEF = 2
 };
 
 struct list_node
