class A {
    public $a;

    public function bind(&$a) {
        $this->a = &$a;
    }

    public function set($a) {
        $this->a = $a;
    }
}

echo "start: " . memory_get_usage(true). "\n";

$a = new A();
$b = array();
for ($i = 0; $i < 100000; $i++) {
    $b[] = array('c' => $i);
}
echo "generated: " . memory_get_usage(true). "\n";

$a->bind($b);
echo "binded: " . memory_get_usage(true). "\n";

foreach ($a->a as $i) {
    foreach ($i as $inner) {
        continue;
    }
}
echo "iterated: " . memory_get_usage(true). "\n\n";

unset($a);
unset($b);
echo "cleanup: " . memory_get_usage(true). "\n";

echo "\n";

$a = new A();
$b = array();
for ($i = 0; $i < 100000; $i++) {
    $b[] = array('c' => $i);
}
echo "generated: " . memory_get_usage(true). "\n";

$a->set($b);
echo "set: " . memory_get_usage(true). "\n";

foreach ($a->a as $i) {
    foreach ($i as $inner) {
        continue;
    }
}