Perform exhaustive match in pick_includes_and_builtins
diff --git a/gen/src/write.rs b/gen/src/write.rs
index 08bb1fc..2b4e552 100644
--- a/gen/src/write.rs
+++ b/gen/src/write.rs
@@ -179,7 +179,7 @@
                 out.include.cstdint = true;
                 out.builtin.rust_slice = true;
             }
-            _ => {}
+            Type::Ref(_) | Type::Void(_) => {}
         }
     }
 }