+
+// (C) Copyright John Maddock 2010.
+// Use, modification and distribution are subject to the Boost Software License,
+// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt).
+//
+// See http://www.boost.org/libs/type_traits for most recent version including documentation.
+
+
+#ifndef BOOST_TT_CONDITIONAL_HPP_INCLUDED
+#define BOOST_TT_CONDITIONAL_HPP_INCLUDED
+
+#include <boost/mpl/if.hpp>
+
+namespace boost {
+
+template <bool b, class T, class U>
+struct conditional : public mpl::if_c<b, T, U>
+{
+};
+
+} // namespace boost
+
+
+#endif // BOOST_TT_CONDITIONAL_HPP_INCLUDED