fixes #569; C++ codegen works again

tests/run/tvarious1.nim

@@ -1,7 +1,8 @@
 discard """
   file: "tlenopenarray.nim"
   output: '''1
-0'''
+0
+Whopie'''
 """
 
 echo len([1_000_000]) #OUT 1
@@ -12,3 +13,17 @@ type
 proc `[]`(v: TVector; idx: int): int = TArray(v)[idx]
 var v: TVector
 echo v[2]
+
+# bug #569
+
+import queues
+
+type
+  TWidget = object
+    names: TQueue[string]
+
+var w = TWidget(names: initQueue[string]())
+
+add(w.names, "Whopie")
+
+for n in w.names: echo(n)