Not able to call a function using function pointer [duplicate]

Question

Possible Duplicate:
How to call a function using pointer-to-member-function

Analyzer.h

class Analyzer
{
public :

    void viku();
    void Bibek();
    void vivek();
    void (Analyzer::*point)();

    Analyzer(){

    }
    ~Analyzer(){

    }

};

Analyzer.cpp

    using namespace std     
    #include"Analyzer.h"
    void Analyzer::viku(){
        cout<<"Hello viku";
    }
    void Analyzer::vivek(){
        point =&Analyzer::viku; 
        Bibek();   
    }
    void Analyzer::Bibek(){
           point();//Errror
        cout<<"Bibek";
    }

During compilation it shows the following error:

error C2064: term does not evaluate to a function taking 0 arguments.

Can anyone please tell me how to avoid this?

You should read the chapter in your book about pointers-to-member-functions, because that is not a normal function pointer. -1 for no prior research. — Lightness Races in Orbit
– Lightness Races in Orbit, Commented Dec 28, 2012 at 11:57
I read it but still not able to find out that's why i have posted this here . According to me i have done everything correct 1-both the function pointer and function's signature is same . and the calling convention too . Then where i am getting the problem ? — Viku
– Viku, Commented Dec 28, 2012 at 12:04
not related to your problem, but important: Avoid using using namespace in header files, better yet: don't use it at all. It might cause naming conflicts. — stefan
– stefan, Commented Dec 28, 2012 at 12:18
@LightnessRacesinOrbit: It looks like he understands the difference, but not that point(); doesn't work from a member function where viku(); would. +1 for a reasonable question. — Mike Seymour
– Mike Seymour, Commented Dec 28, 2012 at 12:18
@MikeSeymour: Please hover over the downvote icon and notice that lack of research is a reason to downvote. How to use pointers-to-member-functions is covered in any good C++ book and thus should not need to be asked again here. Or, if nothing else, it's a duplicate. — Lightness Races in Orbit
– Lightness Races in Orbit, Commented Dec 28, 2012 at 12:26

StoryTeller - Unslander Monica · Accepted Answer · 2012-12-28 13:34:17Z

3

Pointers to member functions are different than normal function pointer. You need an instance to call them:

#include <iostream>

class A
{
public:
  int foo()
  {
      std::cout << "A::foo here, you can have 42" << std::endl;
      return 42;
  }
};

int main ()
{
  int (A::* point)() = &A::foo;
  A a;

  (a.*point)();
}

In your case, you'd need to do something like the following:

(this->*point)()

edited Dec 28, 2012 at 13:34

answered Dec 28, 2012 at 11:58

StoryTeller - Unslander Monica

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