From 1f3ce26421f73916aa978c67ab90cdf68218120d Mon Sep 17 00:00:00 2001
From: Charles Blake <cblake@csail.mit.edu>
Date: Sat, 7 Feb 2015 13:13:03 -0500
Subject: [PATCH] Address Andreas' complaint about code duplication.

---
 lib/pure/collections/sets.nim | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index 3e462f73f..33fec1a18 100644
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -246,8 +246,9 @@ proc incl*[A](s: var HashSet[A], other: HashSet[A]) =
   for item in other: incl(s, item)
 
 template doWhile(a: expr, b: stmt): stmt =
-  b
-  while a: b
+  while true:
+    b
+    if not a: break
 
 proc excl*[A](s: var HashSet[A], key: A) =
   ## Excludes `key` from the set `s`.