Update count() method.

src/Collection.php

@@ -15,6 +15,7 @@
 use drupol\collection\Operation\Collapse;
 use drupol\collection\Operation\Combine;
 use drupol\collection\Operation\Contains;
+use drupol\collection\Operation\Count;
 use drupol\collection\Operation\Filter;
 use drupol\collection\Operation\First;
 use drupol\collection\Operation\Flatten;
@@ -112,7 +113,7 @@ public function contains($key): bool
      */
     public function count(): int
     {
-        return \iterator_count($this->getIterator());
+        return $this->run(Count::with());
     }
 
     /**

src/Operation/Count.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace drupol\collection\Operation;
+
+use drupol\collection\Contract\Collection as CollectionInterface;
+
+/**
+ * Class Count.
+ *
+ * Be careful, this will only work with finite collection sets.
+ */
+final class Count extends Operation
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function run(CollectionInterface $collection)
+    {
+        return \iterator_count($collection->getIterator());
+    }
+}