c++ - Generic object with common baseclass to std::function

Im trying to create a signal handling class with a Qt inspired interface like this

class MessageConsumer {};

class MessageHandler {
public:
  static int Connect(int, MessageConsumer* obj, std::function handler) { 

    // Add callback to handler 
    }      
};

class A : public MessageConsumer {
public:
  void handleIt(void) {
    // Do stuff
  }
};


int main(void) {
  A a;
  MessageHandler::Connect(1, &a, &A::handleIt);
  return 0;
}

But keep getting the compiler error

main.cpp: In function ”int main()”:
main.cpp:71:46: error: no matching function ”MessageHandler::Connect(int, A*, void (A::)())”
MessageHandler::Connect(1, &a, &A::handleIt);
^
main.cpp:53:5: anm: candidate: static int MessageHandler::Connect(int, MessageConsumer, std::function)
int MessageHandler::Connect(int, MessageConsumer* obj, std::function handler) {
^~~~~~~~~~~~~~
main.cpp:53:5: anm: no known conversion for argument 3 from ”void (A::*)()” to ”std::function”

Is there a way to solve this error without defining templates, i do not want use templating in the interface, i.e.

MessageHandler::Connect(1, &a, &A::handleIt)