From 8c3deb14ec2c4e5f5ed47646f12a3fcc7f31e834 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Thu, 29 Jun 2017 08:54:01 -0700
Subject: [PATCH] nit

---
 pitfall/restructure/struct.rkt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pitfall/restructure/struct.rkt b/pitfall/restructure/struct.rkt
index 9829646b..75d8eee2 100644
--- a/pitfall/restructure/struct.rkt
+++ b/pitfall/restructure/struct.rkt
@@ -83,7 +83,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
 
   (define/override (size [input-hash (mhash)] [parent #f] [includePointers #t])
     (for/sum ([(key type) (in-dict fields)])
-      (define val (hash-ref input-hash key #f))
+      (define val (ref input-hash key))
       (define args (if val (list val) empty))
       (send type size . args))))