From 9d0ddc4709108c8e7e5a9e5a0109091e31e27de7 Mon Sep 17 00:00:00 2001
From: Andrzej Krzemienski <akrzemi1@gmail.com>
Date: Wed, 1 Nov 2017 06:44:26 +0100
Subject: [PATCH] fixed regression on compilers w/o type trait support

---
 include/boost/optional/optional.hpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/boost/optional/optional.hpp b/include/boost/optional/optional.hpp
index 4a237a1..b955fb7 100644
--- a/include/boost/optional/optional.hpp
+++ b/include/boost/optional/optional.hpp
@@ -827,13 +827,21 @@ struct is_type_trivially_copyable
 } // namespace optional_detail
 
 namespace optional_config {
-  
+
+#ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES  
 template <typename T>
 struct is_type_trivial
   : boost::conditional< (optional_detail::is_type_trivially_copyable<T>::value && BOOST_HAS_TRIVIAL_CONSTRUCTOR(T)) ||
                         (boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value)
                       , boost::true_type, boost::false_type>::type
 {};
+#else
+template <typename T>
+struct is_type_trivial
+  : boost::conditional<(boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value)
+                      , boost::true_type, boost::false_type>::type
+{};
+#endif
 
 } // namespace optional_config