Online PHP editor | refs for YcKua

<?php class Item { private $id; public function __construct(int $id) { $this->id = $id; } public function id() : int { return $this->id; } } class Collection { private $items = []; public function __construct(Item ...$items) { $this->items = $items; } public function item() : Generator { yield from $this->items; } } $items = []; for ($i=0; $i<10; $i++) { $items[] = new Item($i); } $collection = new Collection(...$items); $generator = $collection->item(); printf("\nThe Collection::item() method returns a type of %s, as expected\n", get_class($generator)); printf("However, it yields the following:\n\n"); foreach ($generator as $item) { printf("\tClass: %s. Calling id() method returns %d (%s)\n", get_class($item), $item->id(), gettype($item->id())); } printf("\n\nIt doesn't appear to be possible to hint the yielded type\n\n");