Question

for example consider this single factorial:

int factorial(int number) {
  int temp;
  if(number <= 1) return 1;
  temp = number * __FUNCTION__(number - 1);
  return temp;
}

It gives:

error: '__FUNCTION__' cannot be used as a function

The idea is using this constant instead of function name so if I change the name of the function it wouldn’t be needed to look in the rest of the code to update the name wherever function calls itself.

Answer 1

You can’t because __FUNCTION__ is probably reserved by the implementation, and it expands to the function name (in string format).

Besides changing the name, you might want to use a macro instead of a constant:

#define MY_FUNCTION factorial

int MY_FUNCTION(int number) {
  int temp;
  if(number <= 1) return 1;
  temp = number * MY_FUNCTION(number - 1);
  return temp;
}

Personally, I don’t see the point of this. Granted, you only change the function name in one place, but is it worth it?