It is also defined for floats.

Using it seems like a bad move though -- for large values it can round back to the input value.

Indeed, the following stupid test program works, although it may heat up your laptop slightly.

    #include <stdio.h>

    void main()
    {
      float C   = 1.0f;
      float Cin = 0.0f;
      int i=0;

      while (Cin != C)
      {
        i++;
        Cin = C;
        C++;
      }
      printf("%i %e\n", i, C/C++);
    }

And, it finally lets us confirm what the mathematicians never could. When does the limit happen? 16777216. No further questions.