implement a general method later in c++ -

i know following code won't compile, posted anyway because exemplifies trying accomplish.

typedef struct {     void actionmethod(); }object;  object myobject;  void myobject.actionmethod() {     // something; }  object anotherobject;  void anotherobject.actionmethod() {     // else; }  main() {     myobject.actionmethod();     anotherobject.actionmethod(); } 

basically want kind of delegate. there easy way this?

i can't include <functional> header , use std::function either. how can this?

for example:

#include <iostream>  using namespace std;  struct anobject {     void (*actionmethod)(); };  void anactionmethod() {     cout << "this 1 implementation" << endl; }  void anotheractionmethod() {     cout << "this implementation" << endl; }  int main() {     anobject myobject, anotherobject;     myobject.actionmethod = &anactionmethod;     anotherobject.actionmethod = &anotheractionmethod;      myobject.actionmethod();     anotherobject.actionmethod();      return 0; } 

output:

this 1 implementation  implementation