How to pass a function pointer that points to constructor?

Question

I'm working on implementing a reflection mechanism in C++. All objects within my code are a subclass of Object(my own generic type) that contain a static member datum of type Class.

class Class{ public:    Class(const std::string &n, Object *(*c)()); protected:    std::string name;     // Name for subclass    Object *(*create)();  // Pointer to creation function for subclass }; 

For any subclass of Object with a static Class member datum, I want to be able to initialize 'create' with a pointer to the constructor of that subclass.

Answer 1

You cannot take the address of a constructor (C++98 Standard 12.1/12 Constructors - "12.1-12 Constructors - "The address of a constructor shall not be taken.")

Your best bet is to have a factory function/method that creates the Object and pass the address of the factory:

class Object;  class Class{ public:    Class(const std::string &n, Object *(*c)()) : name(n), create(c) {}; protected:    std::string name;     // Name for subclass    Object *(*create)();  // Pointer to creation function for subclass };  class Object {};  Object* ObjectFactory() {     return new Object; }    int main(int argc, char**argv) {     Class foo( "myFoo", ObjectFactory);      return 0; }