1--TEST-- 2Non-ref generators cannot be iterated by-ref 3--FILE-- 4<?php 5 6function gen() { yield; } 7 8$gen = gen(); 9foreach ($gen as &$value) { } 10 11?> 12--EXPECTF-- 13Fatal error: Uncaught exception 'Exception' with message 'You can only iterate a generator by-reference if it declared that it yields by-reference' in %s:%d 14Stack trace: 15#0 %s(%d): unknown() 16#1 {main} 17 thrown in %s on line %d 18 19