C++: Array of member function pointers to different functions

Question

I have a class A which contains member functions foo() and bar() which both return a pointer to class B. How can I declare an array containing the functions foo and bar as a

Answer 1

What you're looking for are pointers to member functions. Here is a short sample that shows their declaration and use:

#include 

class B {
public:
  B(int foo): foo_(foo) {
    std::cout << "Making a B with foo_ = " << foo_ << std::endl;
  }
  ~B(void) {
    std::cout << "Deleting a B with foo_ = " << foo_ << std::endl;
  }
  int foo_;
};

class A {
public:
  A(void) {
    funcs_[0] = &A::foo;
    funcs_[1] = &A::bar;
  }

  B* foo(void) {
    return new B(3);
  }

  B* bar(void) {
    return new B(5);
  }

  // Typedef for the member function pointer, for everyone's sanity.
  typedef B* (A::*BMemFun)(void);
  BMemFun funcs_[2];
};

int main(int argc, char *argv[]) {
  A a;
  for (int i = 0; i < 2; ++i) {
    A::BMemFun func = a.funcs_[i];
    // Call through the member function pointer (the .* operator).
    B* b = (a.*func)();
    delete b;
  }
  return 0;
}

The C++ FAQ section on pointers to member functions is where I found all this information.