Re: EnumSet and varargs

"John B. Matthews" <nospam@nospam.invalid>
Wed, 17 Sep 2008 07:48:45 -0400
In article <>,
 Roedy Green <> wrote:

On Tue, 16 Sep 2008 23:39:51 GMT, Wojtek <> wrote, quoted
or indirectly quoted someone who said :

closest is,%20E...)
, but it needs an initial single parameter. null is not an option.

All those variants are just ways of handling an EnumSet with a small
number of elements more efficiently.


Wojtek : In addition to the vararg constructor, consider offering an
EnumSet constructor. This would allow clients to use EnumSet's set
operations, e.g. union, intersection, complement, etc:

import java.util.*;

public class EnumTest {

    enum Bar { ONE, TWO, THREE, FOUR; }

    public EnumTest(EnumSet<Bar> bars) {

    public EnumTest(Bar... bars) {
        List<Bar> barList = Arrays.asList(bars);
        EnumSet<Bar> barSet = EnumSet.copyOf(barList);
    private static void showBars(EnumSet<Bar> bars) {
        for (Bar b : bars) System.out.print( + " ");

    public static void main(String[] args) {
        EnumTest test1 = new EnumTest(
        Bar[] bars = { Bar.ONE, Bar.TWO, Bar.FOUR };
        EnumTest test2 = new EnumTest(bars);

John B. Matthews
trashgod at gmail dot com
home dot woh dot rr dot com slash jbmatthews

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