3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php interface I { } class C extends I { } interface BI { function x(): I; } class BC implements BI { function x(): C; }
based on CDTZQ
Output for 5.6.0 - 5.6.30, 7.0.0 - 7.1.7
Fatal error: Class C cannot extend from interface I in /in/MT3XI on line 8
Process exited with code 255.
Output for hhvm-3.15.4
Fatal error: Uncaught Error: Non-abstract method BC::x() must contain body in /in/MT3XI:14 Stack trace: #0 {main}
Process exited with code 255.