From 493961307089ec474a94271605e2905a46227f28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andrzej=20Krzemie=C5=84ski?= <akrzemi1@gmail.com>
Date: Tue, 6 Oct 2015 09:17:14 +0200
Subject: [PATCH] added missing ifdef

---
 include/boost/optional/detail/optional_reference_spec.hpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/boost/optional/detail/optional_reference_spec.hpp b/include/boost/optional/detail/optional_reference_spec.hpp
index f64e581..61e7eee 100644
--- a/include/boost/optional/detail/optional_reference_spec.hpp
+++ b/include/boost/optional/detail/optional_reference_spec.hpp
@@ -18,6 +18,8 @@ namespace boost {
 
 namespace detail {
 
+#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
+
 template <class From>
 void prevent_binding_rvalue()
 {
@@ -35,6 +37,8 @@ BOOST_DEDUCED_TYPENAME boost::remove_reference<T>::type& forward_reference(T&& r
     return boost::forward<T>(r);
 }
 
+#endif // BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
+
 template <class T>
 struct is_optional_
 {