Remove use of boost::blank, close #8622

test/functional/unfused.cpp

@@ -10,8 +10,8 @@
 #include <boost/detail/lightweight_test.hpp>
 
 #include <boost/noncopyable.hpp>
-#include <boost/blank.hpp>
 
+#include <boost/mpl/empty_base.hpp>
 #include <boost/mpl/identity.hpp>
 
 #include <boost/utility/result_of.hpp>
@@ -24,7 +24,7 @@ namespace mpl = boost::mpl;
 
 using boost::noncopyable;
 
-template <class Base = boost::blank>
+template <class Base = boost::mpl::empty_base>
 struct test_func
     : Base
 {