#include <boost/mpl/assert.hpp>
#include <boost/mpl/lambda.hpp>
#include <boost/mpl/not.hpp>
#include <boost/mpl/placeholders.hpp>
#include <boost/mpl/plus.hpp>
using namespace boost::mpl;

// define if your boost distribution includes boost::tti
#define BOOST_TTI
#ifdef BOOST_TTI
#include <boost/tti/detail/dlambda.hpp>
#endif	// BOOST_TTI

struct MetafunctionClass
{
	template<typename T1, typename T2>
	struct apply
	{
		typedef	typename plus<T1,T2>::type type;
	};
};

// work correctly:
BOOST_MPL_ASSERT((is_lambda_expression<plus<_1, _2> >));
#ifdef BOOST_TTI
BOOST_MPL_ASSERT((boost::tti::detail::is_lambda_expression<MetafunctionClass>));
#endif // BOOST_TTI
// does not work correctly
BOOST_MPL_ASSERT((not_<is_lambda_expression<MetafunctionClass> >));

int main(int argc, char * argv[])
{
}