Add skeleton headers for things not yet implemented.

include/boost/mp11/function.hpp

@@ -0,0 +1,23 @@
+#ifndef BOOST_MP11_FUNCTION_HPP_INCLUDED
+#define BOOST_MP11_FUNCTION_HPP_INCLUDED
+
+//  Copyright 2015 Peter Dimov.
+//
+//  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
+
+namespace boost
+{
+
+// mp_plus<T...>
+// mp_not<T>
+// mp_all<T...>
+// mp_and<T...>
+// mp_any<T...>
+// mp_or<T...>
+
+} // namespace boost
+
+#endif // #ifndef BOOST_MP11_FUNCTION_HPP_INCLUDED