Method demo

examples/demo.php:2837–2855

()

class PassByReferenceDemo
{
    public function demo(): void
    {
        // When a function takes a typed &$var parameter, the variable
        // acquires that type after the call.
        initPen($pen);
        $pen->write();                    // $pen is now Pen

        // Static method calls with by-ref parameters:
        PenFactory::create($staticPen);
        $staticPen->write();              // $staticPen is now Pen

        // Constructor calls with by-ref parameters:
        new PenBuilder($ctorPen);
        $ctorPen->write();                // $ctorPen is now Pen

        // Instance method calls ($this->method) with by-ref parameters:
        $this->init($thisPen);
        $thisPen->write();                // $thisPen is now Pen
    }

    private function init(?Pen &$pen): void
    {