Sure, 0.1 can be represented exactly. But that's about the only issue with floating-point that that solves.
He could also use fdlibm ( http://netlib.org/fdlibm/index.html ), at least for anything other than primitive operations. But, again, it trades performance for consistency.
Sure, 0.1 can be represented exactly. But that's about the only issue with floating-point that that solves.