member member function pointers

im trying to create a member function pointer, but the problem is that i need to make that pointer a member of the class as well. heres a sample of what im trying to:

Code:

//gfxclass.h

class gfxclass
{
public:
    //this is my member function pointer
    int (gfxclass::*RGB)(int, int, int);

    int initgfx(void);
private:
    //here are the two functions it could point to
    int gfx1(int r, int g, int b);
    int gfx2(int r, int g, int b);
};

Code:

//gfxclass.cpp

#include "gfxclass.h"

int gfxclass::init(void)
{
    if(whatever)
        RGB = gfx1;
    else
        RGB = gfx2;
}

int gfxclass::gfx1(int r, int g, int b)
{
//whatever, do stuff
}

int gfxclass::gfx2(int r, int g, int b)
{
//whatever
}

Code:

//main.cpp

#include "gfxclass.h"

gfxclass gclass;

int main()
{
    gclass.init();

    int temp = (gclass.*RGB)(0,0,0);

    return 0;
}

when i go to compile, i get an undeclared identifier error on my call to RGB. ive managed to get it to compile with the member function pointer not being part of the class, but i need it to be a member. any help would be appreciated

http://www.function-pointer.org/

Using a member function pointer to execute a member function has a wacked syntax. By the way, I've never been able to get the syntax in those tutorials to work(VC++6).

The member function pointer is accessed using an object of the class: gclass.RGB. To get the function, you need to dereference that, which gives you: *gclass.RGB. Now, you need to call that function with a class object:

(gclass.*gclass.RGB)(0, 0, 0);

The parentheses matter. Since *gclass.RGB is the actual member function, you can even create a second object, say gclass2, to call the member function represented by *gclass.RGB:

(gclass2.*gclass.RGB)(0,0,0);

tyvm for your help! that problems been bugging me for a while now, but it finally compiled properly