From 3a7dd428fe4e19a07426caf76cad6eb314703b6f Mon Sep 17 00:00:00 2001
From: Robby Findler <robby@racket-lang.org>
Date: Thu, 20 Jan 2005 16:33:04 +0000
Subject: [PATCH] .

original commit: 58883226424b22d866dd6fd642f05431e0aee16a
---
 collects/mzlib/contract.ss | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/collects/mzlib/contract.ss b/collects/mzlib/contract.ss
index 3127811..7c8a1da 100644
--- a/collects/mzlib/contract.ss
+++ b/collects/mzlib/contract.ss
@@ -2989,7 +2989,17 @@ add struct contracts for immutable structs?
                   val))
                (delay (p-app (force val))))))))))
   
+  #|
+   as with copy-struct in struct.ss, this first begin0
+   expansion "declares" that struct/c is an expression
+   preventing further expansion until the internal definition
+   context is sorted out.
+  |#
   (define-syntax (struct/c stx)
+    (syntax-case stx ()
+      [(_ . args) (syntax (begin0 (do-struct/c . args)))]))
+  
+  (define-syntax (do-struct/c stx)
     (syntax-case stx ()
       [(_ struct-name args ...)
        (and (identifier? (syntax struct-name))