<?php

final class ListOfId implements \Iterator, \Countable
{
    private $values;

    public function __construct(array $values = [])
    {
        $this->values = array_values(array_filter(array_unique(array_map('intval', $values))));
    }

    public function count()
    {
        return \count($this->values);
    }

    public function isEmpty()
    {
        return $this->count() > 0;
    }

    public function toArray()
    {
        return $this->values;
    }

    public function current()
    {
        return \current($this->values);
    }

    public function next()
    {
        return \next($this->values);
    }

    public function key()
    {
        return \key($this->values);
    }

    public function valid()
    {
        return \key($this->values) !== null;
    }

    public function rewind()
    {
        return \reset($this->values);
    }
}