- assert: documentation ( source)
- var_dump: documentation ( source)
<?php
class FooCls {}
function foo(): iterable
{
yield new FooCls => 1;
yield new FooCls => 2;
yield new FooCls => 3;
yield new FooCls => 4;
}
$iterator = foo();
assert($iterator instanceof Iterator);
var_dump($iterator->key());