/**
* Fast Path set difference for comparison with another IntHashSet.
*
* <p>NB: garbage free in the identical case, allocates otherwise.
*
* @param other the other set to subtract
* @return null if identical, otherwise the set of differences
*/
public IntHashSet difference(final IntHashSet other) {
Objects.requireNonNull(other);
IntHashSet difference = null;
final int missingValue = this.missingValue;
for (final int value : values) {
if (value != missingValue && !other.contains(value)) {
if (difference == null) {
difference = new IntHashSet(size, missingValue);
}
difference.add(value);
}
}
return difference;
}
