A DESCRIPTION OF THE REQUEST :
I propose, for most of the Collection implementations (eg. HashSet, TreeSet, LinkedList, ArrayList, etc) something like:

class HashSet<E> ... {
  public HashSet(E item, E ... items) {
    add(item);
    for (E e : items)
      add(e);
  }
  ...
}


JUSTIFICATION :
It's the best kind of syntactic sugar.  It's not too sweet and doesn't require any new syntax.  Collections often have only one or a few members, and they are kind of annoying to set up.  You can either do things verbosely (and therefore error-pronely) like this:

class Something {
  public static final Set<Something> someSomethings = new HashSet<Something>();
  static {
    someSomethings.add(Something.THING0);
    someSomethings.add(Something.THING1);
  }
}

...or you end up with kludges like in EnumSet<E>:

public static <E extends Enum<E>> EnumSet<E> of(E e)
public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2)
public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2, E e3)
public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2, E e4, E e5)

That is begging for varargification.  Granted, those are not constructors, but that's just an implementation detail of EnumSet.  Sets in general (and indeed, most Collections) would benefit from a varargs constructor.
###@###.### 2005-03-24 19:14:25 GMT