rem: test->add( BOOST_TEST_CASE(&assign_test) ); test->add( BOOST_TEST_CASE(&assign_test_ref) );
add: assign_test(); assign_test_ref();
context: void assign_action_test(boost::unit_test_framework::test_suite* test){    test->add( BOOST_TEST_CASE(&assign_test) );    test->add( BOOST_TEST_CASE(&assign_test_ref) );}