Fixed the printing of O_CONS nodes

1 files changed, 2 insertions, 2 deletions

diff --git a/src/op.h b/src/op.h
index 94df154e..ea787d8c 100644
--- a/src/op.h
+++ b/src/op.h
@@ -243,10 +243,10 @@ private:
       checked_delete(this);
   }
 
-  friend inline void intrusive_ptr_add_ref(op_t * op) {
+  friend inline void intrusive_ptr_add_ref(const op_t * op) {
     op->acquire();
   }
-  friend inline void intrusive_ptr_release(op_t * op) {
+  friend inline void intrusive_ptr_release(const op_t * op) {
     op->release();
   }