Function operator +

gecode/float/val.hpp:163–166

   */

  forceinline FloatVal
  operator +(const FloatVal& x) {
    return FloatVal(+x.x);
  }
  forceinline FloatVal
  operator -(const FloatVal& x) {
    FloatNum mmi = (x.min() == 0.0) ? 0.0 : -x.min();