--TEST-- Bug #73954 (NAN check fails on Alpine Linux with musl) --FILE-- <?php var_dump(NAN); var_dump(is_nan(NAN)); function takes_int(int $int) { } takes_int(log(tan(3.14))); ?> --EXPECTF-- float(NAN) bool(true) Fatal error: Uncaught TypeError: Argument 1 passed to takes_int() must be of the type integer, float given, called in %s on line 9 and defined in %s:6 Stack trace: #0 %s(9): takes_int(NAN) #1 {main} thrown in %s on line 6