#if defined(BOOST_MSVC) || defined(BOOST_INTEL)
#include <boost/type_traits/is_pod.hpp>
#include <boost/type_traits/is_volatile.hpp>
+#include <boost/type_traits/is_reference.hpp>
#endif
-#if defined(__GNUC__) || defined(__clang)
+#if defined(__GNUC__) || defined(__clang__)
#include <boost/type_traits/is_constructible.hpp>
#include <boost/type_traits/is_volatile.hpp>
#endif