Method demo

examples/demo.php:273–291

(ScaffoldingMotor $m)

    public function sport(): void {}

    public function demo(ScaffoldingMotor $m): void
    {
        // instanceof self — narrows to InstanceofSelfDemo
        assert($m instanceof self);
        $m->cruise();                             // inherited from ScaffoldingSedan
        $m->sport();                              // own method via self narrowing

        // instanceof static — narrows to InstanceofSelfDemo
        $x = getUnknownValue();
        if ($x instanceof static) {
            $x->sport();                          // narrowed to static (this class)
        }

        // instanceof parent — narrows to ScaffoldingSedan
        $y = getUnknownValue();
        if ($y instanceof parent) {
            $y->cruise();                         // narrowed to parent (ScaffoldingSedan)
        }
    }
}