1--TEST-- 2Return types allowed in namespace 3--FILE-- 4<?php 5 6namespace Collections; 7 8interface Collection { 9 function values(): Collection; 10} 11 12class Vector implements Collection { 13 function values(): Collection { 14 return $this; 15 } 16} 17 18$v = new Vector; 19var_dump($v->values()); 20--EXPECTF-- 21object(Collections\Vector)#%d (%d) { 22} 23