From 9d6b7babae5daaeb9b45e69656b580c9d212ea4a Mon Sep 17 00:00:00 2001
From: Wesley Kerfoot <wjak56@gmail.com>
Date: Sun, 19 Jan 2020 23:49:17 -0500
Subject: [PATCH] use add instead of seq concatenation

---
 src/nimwin.nim | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/nimwin.nim b/src/nimwin.nim
index dd8e126..5f4fb1e 100644
--- a/src/nimwin.nim
+++ b/src/nimwin.nim
@@ -34,7 +34,7 @@ proc gcWindows(display : PDisplay) =
 
 proc ignoreBadWindows(display : PDisplay, ev : PXErrorEvent) : cint {.cdecl.} =
   # resourceID maps to the Window's XID
-  invalidWindows &= @[ev.resourceID]
+  invalidWindows.add(ev.resourceID)
   0
 
 proc getDisplay : PDisplay =