diff --git a/boost/preprocessor/control/iif.hpp b/boost/preprocessor/control/iif.hpp
new file mode 100644
index 0000000..fd07817
--- /dev/null
+++ b/boost/preprocessor/control/iif.hpp
@@ -0,0 +1,34 @@
+# /* **************************************************************************
+#  *                                                                          *
+#  *     (C) Copyright Paul Mensonides 2002.
+#  *     Distributed under 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 for most recent version. */
+#
+# ifndef BOOST_PREPROCESSOR_CONTROL_IIF_HPP
+# define BOOST_PREPROCESSOR_CONTROL_IIF_HPP
+#
+# include <boost/preprocessor/config/config.hpp>
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MWCC()
+#    define BOOST_PP_IIF(bit, t, f) BOOST_PP_IIF_I(bit, t, f)
+# else
+#    define BOOST_PP_IIF(bit, t, f) BOOST_PP_IIF_OO((bit, t, f))
+#    define BOOST_PP_IIF_OO(par) BOOST_PP_IIF_I ## par
+# endif
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_MSVC()
+#    define BOOST_PP_IIF_I(bit, t, f) BOOST_PP_IIF_ ## bit(t, f)
+# else
+#    define BOOST_PP_IIF_I(bit, t, f) BOOST_PP_IIF_II(BOOST_PP_IIF_ ## bit(t, f))
+#    define BOOST_PP_IIF_II(id) id
+# endif
+#
+# define BOOST_PP_IIF_0(t, f) f
+# define BOOST_PP_IIF_1(t, f) t
+#
+# endif