3v4l.org

run code in 300+ PHP versions simultaneously
<?php function gen(): Generator { yield new stdClass() => 'foo'; yield ['a'] => 'foo'; yield gen2() => 'foo'; } function gen2(): Generator { yield 'bar'; } gen(); foreach(gen() as $key => $value) { var_dump($key, $value); }
based on Rftqi
Output for 7.3.0 - 7.3.27, 7.4.0 - 7.4.16, 8.0.0 - 8.0.3
object(stdClass)#3 (0) { } string(3) "foo" array(1) { [0]=> string(1) "a" } string(3) "foo" object(Generator)#3 (0) { } string(3) "foo"