Quote:Original post by Decrius
I have a heterogeneous array of non-templated class Base, I then have a templated class Derived, it holds variables of type T. I then have a function which walks the array. Through a boolean in the Base class I know I can cast the array element to Derived, I only use other variables in Derived, not variables of type T.

I am not able, as function caller, to pass which type T is. So is there something so I don't have to care about what T is? Or can I simply cast it as Derived<void> *array_element = array[element]; or something?

Thanks

PS: in fact, the variable in Derived is a member function pointer as (T::*member_function)()

struct Base {  bool is_derived;  Base(bool is_derived = false): is_derived(is_derived) {}};template <typename T>struct Derived<T>: Base {  void (T::*func)();  Derived(void (T::*func)()): func(func), Base(true) {}};std::vector<Base*> function_wrappers;for (  std::vector<Base*>::iterator it = function_wrappers.begin(),  end = function_wrappers.end(); it != end; ++it) {  // You want to extract the Derived instance and invoke its member function  // upon a T, without knowing what type T is?}

struct Base {  virtual void operator()() = 0;  virtual ~Base() {}};template <typename T>struct Derived<T>: Base {  void (T::*func)();  T* target;  Derived(void (T::*func)(), const T& target): func(func), target(&target) {}  void operator()() { (target.->func)(); }};std::vector<Base*> function_wrappers;for (  std::vector<Base*>::iterator it = function_wrappers.begin(),  end = function_wrappers.end(); it != end; ++it) {  (*it)();}