Actually, it is not true that integers up to a certain value are exactly represented by floats. They can be, but usually aren't. You can represent integers exactly in a denormalised float, but typically not in a normalised one. Usually, your floats will be normalised, so they are off.

This little annoyance only matters in comparisons, all you have to do is to cast everything to float (eg write 2.0f not 2.0), and then compare. That should give the expected results.