1  template < typename T > struct integral_c {
       2    static const T value = 0;
       3  };
       4  struct is_reference:integral_c < bool > { };
       5  template < class > struct is_function_ptr_helper { };
       6  template < bool > struct is_function_chooser;
       7  
       8  template <> struct is_function_chooser <0 >
       9  {
      10    template < typename T > struct result_:is_function_ptr_helper < T * > { };
      11  };
      12  
      13  template < typename T > struct is_function_impl:is_function_chooser <
      14    is_reference::value >::result_ < T > { };