Add ref(x) tests to mem_fn_dm_test

test/mem_fn_dm_test.cpp

@@ -8,16 +8,17 @@
 #endif
 
 //
-//  mem_fn_dm_test.cpp - data members
+// mem_fn_dm_test.cpp - data members
 //
-//  Copyright (c) 2005 Peter Dimov
+// Copyright 2005, 2024 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)
 //
 
 #include <boost/mem_fn.hpp>
+#include <boost/core/ref.hpp>
 #include <boost/core/lightweight_test.hpp>
 
 struct X
@@ -52,5 +53,11 @@ int main()
     BOOST_TEST( boost::mem_fn( &X::m )( cx ) == 603 );
     BOOST_TEST( boost::mem_fn( &X::m )( pcx ) == 603 );
 
+    BOOST_TEST_EQ( boost::mem_fn( &X::m )( boost::ref( x ) ), 603 );
+    BOOST_TEST_EQ( boost::mem_fn( &X::m )( boost::cref( x ) ), 603 );
+
+    // boost::mem_fn( &X::m )( boost::ref( x ) ) = 704;
+    // BOOST_TEST_EQ( x.m, 704 );
+
     return boost::report_errors();
 }