Determine if a class has a function

Using a trick (described by Olivier Langlois ) I can tell if a class is of a specific type:

template<typename T> struct hasType
{
    template<typename C> static char test( typename C::Type );
    template<typename C> static char* test(...);
    enum{ Value= sizeof(test<T>(0))==1 };
};

      

        
        
        
      

    

I can also tell if a class has a variable:

template<typename T> struct hasType
{
    template<typename C> static char test( decltype(C::var) );
    template<typename C> static char* test(...);
    enum{ Value= sizeof(test<T>(0))==1 };
};

      

        
        
        
      

    

However, decltype(c::func)

nur decltype(c::func())

(which depends on parameters) does not work for member functions . Is there a way to do this, or do I need to create a functor in each class and detect it using typename C::functor

?

Edit : You are both correct, but since I also have to test for the type, I will use decltype(&C::func)

(which obviously needs to be a pointer).