From ddf5593e4454ea49221905ddaca78416d5f31939 Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Wed, 22 Aug 2018 18:24:49 -0600
Subject: [PATCH] revert is_undefined back to ref match, re: #44

---
 src/prolog/ast.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/prolog/ast.rs b/src/prolog/ast.rs
index 63aefed6..23425e9a 100644
--- a/src/prolog/ast.rs
+++ b/src/prolog/ast.rs
@@ -1575,7 +1575,7 @@ impl CodeIndex {
     pub fn is_undefined(&self) -> bool {
         let index_ptr = &self.0.borrow().0;
 
-        if let IndexPtr::Undefined = index_ptr {
+        if let &IndexPtr::Undefined = index_ptr {
             true
         } else {
             false
-- 
2.54.0