@new = map { $p ne $_ ? $p = $_ : () } @orig;

##</code><code>##

    $p = 'supercalifragilistic';
    @new = map  { $p ne $_ ? $p = $_ : () } @orig;

##</code><code>##

    use strict;
    sub uniq_adj {
        my $p = 'supercalifragilistic';
        return map  { $p ne $_ ? $p = $_ : () } @_;
    }

    my @orig = (undef, undef, qw(a a b b c 0 c d d u u 0 0 "0" "0" '0' '0'));
    my @new = uniq_adj @orig;

    print "'", join ("' '", @new), "'\n";
    __END__
    Prints --> '' 'a' 'b' 'c' '0' 'c' 'd' 'u' '0' '"0"' ''0''