hphp/hack/test/typecheck/generic_subtyping5.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 TestGeneric<T> {
  13   private T $obj;
  14
  15   public function __construct(T $obj) {
  16     $this->obj = $obj;
  17   }
  18
  19   public function get(): T {
  20     return $this->obj;
  21   }
  22 }
  23
  24 class X<T, Tc as TestGeneric<T> > {
  25   public Vector<T> $vec;
  26
  27   public function __construct(Vector<Tc> $tests) {
  28     $results = Vector {};
  29     foreach ($tests as $test) {
  30       $results[] = $test->get();
  31     }
  32     $this->vec = $results;
  33   }
  34
  35
  36 }
  37
  38 function testBool(bool $arg): void {}
  39
  40 function test(): void {
  41   $objs = Vector {
  42     new TestGeneric(1),
  43     new TestGeneric(2),
  44   };
  45
  46   $results = (new X($objs))->vec;
  47   foreach ($results as $result) {
  48     // Hack should complain it's an int !
  49     testBool($result);
  50   }
  51 }