Hack - Generics Example

Hack - Generics

<?hh

class Box<T>
{
    protected T $data;

    public function __construct(T $data)
    {
        $this->data = $data;
    }

    public function getData(): T
    {
        return $this->data;
    }
}

function main_gen()
{
    $gi = new Box(3);
    $gs = new Box("Hi");
    $ga = new Box(array());
    
    echo $gi->getData()."\n";
    echo $gs->getData()."\n";
    echo $ga->getData()."\n";
}

main_gen();

// Output:

3
Hi
Array