diff --git a/boost/boost/preprocessor/control/if.hpp b/boost/boost/preprocessor/control/if.hpp
new file mode 100644
index 0000000000..71b743d1c2
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+++ b/boost/boost/preprocessor/control/if.hpp
@@ -0,0 +1,31 @@
+# /* Copyright (C) 2001
+#  * Housemarque Oy
+#  * http://www.housemarque.com
+#  *
+#  * Permission to copy, use, modify, sell and distribute this software is
+#  * granted provided this copyright notice appears in all copies. This
+#  * software is provided "as is" without express or implied warranty, and
+#  * with no claim as to its suitability for any purpose.
+#  */
+#
+# /* Revised by Paul Mensonides (2002) */
+#
+# /* See http://www.boost.org for most recent version. */
+#
+# ifndef BOOST_PREPROCESSOR_CONTROL_IF_HPP
+# define BOOST_PREPROCESSOR_CONTROL_IF_HPP
+#
+# include <boost/preprocessor/config/config.hpp>
+# include <boost/preprocessor/control/iif.hpp>
+# include <boost/preprocessor/logical/bool.hpp>
+#
+# /* BOOST_PP_IF */
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
+#    define BOOST_PP_IF(cond, t, f) BOOST_PP_IIF(BOOST_PP_BOOL(cond), t, f)
+# else
+#    define BOOST_PP_IF(cond, t, f) BOOST_PP_IF_I(cond, t, f)
+#    define BOOST_PP_IF_I(cond, t, f) BOOST_PP_IIF(BOOST_PP_BOOL(cond), t, f)
+# endif
+#
+# endif