From 0e09a676cde898ab2a6fcd1da91ebb321979d202 Mon Sep 17 00:00:00 2001
From: Josh Goebel <me@joshgoebel.com>
Date: Wed, 8 Jan 2020 19:46:25 -0500
Subject: [PATCH] regex group should be optional

---
 src/languages/cpp.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/languages/cpp.js b/src/languages/cpp.js
index 78ac5d5634..a6849e47cb 100644
--- a/src/languages/cpp.js
+++ b/src/languages/cpp.js
@@ -8,7 +8,7 @@ Website: https://isocpp.org
 
 function(hljs) {
   function optional(s) {
-    return '(' + s + ')?';
+    return '(?:' + s + ')?';
   }
   var DECLTYPE_AUTO_RE = 'decltype\\(auto\\)'
   var NAMESPACE_RE = '[a-zA-Z_]\\w*::'