Call back functions

[Zaei]

How would I go about creating a callback function. For example, I have function a that takes in a function pointer, and stores it as static, and when i call it again, it would call the function it had stored. How would this be done?

Z.

[HarryW]

Don't really see the problem.... which bit are you having trouble with?

[parksie]

typedef long (*PFNMYFUNCTION)(int, int);

PFNMYFUNCTION pfnTheFunction;

long afunction(int x, int y) {
    return x + y;
}

long func() {
    pfnTheFunction = afunction;

    return (pfnTheFunction)(5, 200);
}

[Zaei]

Nifty, Thanks much.

Z.

[Zaei]

After a romp thorugh ASM land, i figured out an easier way to do this:

int somefunction()
{
  return 10;
}

int callafunc(void* addr)
{
  int retval;
  __asm call [addr];
  __asm mov retval, eax;
  return retval;
}

int main()
{
  return callafunc(somefunction);
}

Z.

[parksie]

Be very careful with calling conventions and passing parameters when doing that

[Zaei]

Quite, but its much more generic. What i was needing it for was to create a simple menu class, and, instead of having to have a million different classes for each menu item type, just be able to create a single class that would call the function address you passed it. No parameters (could be easily set with the class, if i needed them), and no return value (which would be simple to implement anyway =).

Z.

[parksie]

Class member functions have a hidden parameter this

Why can't you use templates?