sub set_bit_offsets {
    my @bitmap = split //, unpack('b*', @_);
    my @offset;
    for my $off (0..$#bitmap) {
        if ($bitmap[$off] == 1) {
            push @offset, $off;
        }
    }
    return @offset;
}

##</code><code>##

sub set_bit_offsets {
    my @bitmap = split //, unpack('b*', @_);
    return grep {$bitmap[$_]} 0..$#bitmap;
}