Doesn't the modulus function avoid most of the issues, here? float RoundToNearestWholeNumber(float f) { if (double.IsNanOrInfinity(f)) return f;

Doesn't the modulus function avoid most of the issues, here? float RoundToNearestWholeNumber(float f) { if (double.IsNanOrInfinity(f)) return f; if (f < 0) return -RoundToNearestWholeNumber(-f); // make sure we're working with a consistent value float v = DiscardExtraPrecision(f); // the fractional part is guaranteed to be representable float r = v % 1; // largest whole value up to v (the floor) float w = v - r; // switch to the ceiling if in the upper half if (r > 0.5) return w + 1; return w; } Feel free to disillusion me.