The interval to merge with this interval.
Note: There is no overload for merge which takes a PosInfInterval, because an interval going from negative infinity to positive infinity is not possible.
assert(NegInfInterval!Date(Date(2012, 3, 1)).merge( NegInfInterval!Date(Date(1999, 7, 6))) == NegInfInterval!Date(Date(2012, 3 , 1))); assert(NegInfInterval!Date(Date(2012, 3, 1)).merge( NegInfInterval!Date(Date(2013, 1, 12))) == NegInfInterval!Date(Date(2013, 1 , 12)));
Returns the union of two intervals