# HG changeset patch
# Parent b8596aa9c05bcf3380c5dbc10163908f03db7ef5

diff --git a/mfbt/Util.h b/mfbt/Util.h
--- a/mfbt/Util.h
+++ b/mfbt/Util.h
@@ -27,7 +27,8 @@ namespace mozilla {
  *   DebugOnly<bool> check = func();
  *   MOZ_ASSERT(check);
  *
- * more concisely than declaring |check| conditional on #ifdef DEBUG, but also
+ * where the side effects of 'func()' are needed regardless of DEBUG, more
+ * concisely than declaring |check| conditional on #ifdef DEBUG, but also
  * without allocating storage space for |check| in release builds.
  *
  * DebugOnly instances can only be coerced to T in debug builds.  In release