[Boost-users] How to use mpl::count and function_types

Hi I'm trying to count the number of parameters in a function-type: cout << boost::mpl::count< boost::function_types::parameter_types< void() > >::value << endl; cout << boost::mpl::count< boost::function_types::parameter_types< void(int) > >::value << endl; cout << boost::mpl::count< boost::function_types::parameter_types< void(int, int) > >::value << endl; This prints: 0 0 0 I would have expected: 0 1 2 What have I done wrong? -- Allan W. Nielsen