What would be a proper invalid value for a pointer?

Question

Suppose I have this code. Your basic \"if the caller doesn\'t provide a value, calculate value\" scenario.

void fun(const char* ptr = NULL)
{
   if (ptr==NULL) {         


        

Answer 1

I agree with all the other answers provided, but here's one more way of handling that, which to me personally looks more explicit, if more verbose:

void fun()
{
  // Handle no pointer passed
}

void fun(const char* ptr)
{
  // Handle non-nullptr and nullptr separately
}