/**
* 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;
}
/**
* IntHashSet specialised variant of {this#containsAll(Collection)}.
*
* @param other int hash set to compare against.
* @return true if every element in other is in this.
*/
public boolean containsAll(final IntHashSet other) {
boolean containsAll = true;
final int missingValue = this.missingValue;
for (final int value : values) {
if (value != missingValue && !other.contains(value)) {
containsAll = false;
break;
}
}
return containsAll;
}