hphp/hack/test/typecheck/functional_box.php

   1 <?hh // strict
   2 /**
   3  * Copyright (c) 2014, Facebook, Inc.
   4  * All rights reserved.
   5  *
   6  * This source code is licensed under the MIT license found in the
   7  * LICENSE file in the "hack" directory of this source tree.
   8  *
   9  *
  10  */
  11
  12 class Box<T> {
  13   private T $x;
  14
  15   public function __construct(T $x) {
  16     $this->x = $x;
  17   }
  18
  19   public function set(T $x): void {
  20     $this->x = $x;
  21   }
  22
  23   public function get(): T {
  24     return $this->x;
  25   }
  26 }
  27
  28 class Ent {}
  29
  30 class EntUser extends Ent {
  31
  32   public function iAmUser(): void {
  33     return;
  34   }
  35 }
  36
  37 class EntPhoto extends Ent {}
  38
  39 class BoxEnt extends Box<Ent> {}