generic_interface.cpp

template<class Interface>
struct GenericInterface
{
    template<class T = Interface>
    auto query_interface() const -> decltype(std::declval<T>().interface(), std::string())
    {
        return i.interface();
    }
    template<class T = Interface>
    auto query_interface() const -> decltype(std::declval<T>().get_my_interface(), std::string())
    {
        return i.get_my_interface();
    }
    template<class T = Interface>
    auto query_interface() const -> decltype(std::declval<T>().myInterface(), std::string())
    {
        return i.myInterface();
    }
    Interface i;
};