SYNOPSIS
        mixed unique_array(object *obarr, string seperator)
        mixed unique_array(object *obarr, string seperator, mixed skip)

DESCRIPTION
        Groups objects together for which the separator function
        returns the same value. obarr should be an array of objects,
        other types are ignored. The separator function is called only
        once in each object in obarr. If no separator function is
        given, 0 is used instead of a return value.
        If a 3rd argument is given and this argument matches the
        return value of the separator function this object will not be
        included in the returned array. The returned array is an array
        of arrays of objects in the form:

        ({ ({ Same1:1, Same1:2, ... Same1:N }),
           ({ Same2:1, Same2:2, ... Same2:N }),
              ....
           ({ SameM:1, SameM:2, ... SameM:N }) })

EXAMPLE
        mixed *arr;
        arr=unique_array(users(), "_query_level", -1);

        This will return an array of arrays holding all user objects
        grouped together by their user levels. Wizards have a user
        level of -1 so they will not appear in the the returned array.

SEE ALSO
        filter(E), map(E)