Thread: ceil mystery

Code:

#include <math.h>
#include <string.h>

int main(void)  {
  double test = (double) strlen("TEST");
  double test2 =(double) ceil(test);
  return 0;
}

This gives me the following error:
undefined reference to `ceil'

This however, works:

Code:

#include <math.h>
#include <string.h>

int main(void)  {
  double test = (double) strlen("TEST");
  (double) ceil(test);
  return 0;
}

Why? What is going on? Oo

Damn...no, I wasnt
I knew there would be something basic I had forgotten to do.