Question

How we can force a function to be called only once. I can do this using some static variable or using boost library, but is there some other way to do this as I don't want to use any of the earlier way. Function is a non member function of any class.

Comments

As far as I know there is no way no standard way by which you can restrict a function not to be called if it is within the scope. The only way is to control by the variables (static as you pointed out), lets wait if someone else know. I am assuming it to be C problem as it is tagged as C.

---

Check this code if it is C++ (found it on net: http://bytes.com/topic/c/answers/753047-calling-function-only-once )

class Init
{
  public:
  Init();
};

LoopedFunc()
{
  static Init init;
}

Answer 1

The base way is to use static variable only something like (which you have already pointed out)

MyFunc()
{
  static bool initialized = false;

  if(!initialized) {
    initialized = true;
  }
  else
  {
     // Print Error and return
     return;
  }
  ....
  ....
}

Also check this link http://stackoverflow.com/questions/4173384/how-to-make-sure-a-function-is-only-called-once