[C++] Handle sinclude
diff --git a/ast.h b/ast.h
index 99c8ae5..2b2b472 100644
--- a/ast.h
+++ b/ast.h
@@ -103,7 +103,7 @@
 
 struct IncludeAST : public AST {
   Value* expr;
-  char op;  // '-' or 0.
+  bool should_exist;
 
   virtual ~IncludeAST();