hphp/test/slow/readonly/readonly_overview_with_attr.php

   1 <?hh
   2 <<file:__EnableUnstableFeatures("readonly")>>
   3 class Foo {
   4   public int $prop = 2;
   5 }
   6 function foo(readonly Foo $x): readonly Foo {
   7   $y = HH\Readonly\as_mut(readonly $x->prop);
   8   var_dump($y);
   9   return $x;
  10 }
  11
  12 class Test {
  13   public function __construct(
  14     public readonly Foo $prop
  15   ) {}
  16
  17   public readonly function get(): readonly Foo {
  18     return readonly $this->prop;
  19   }
  20 }
  21
  22
  23 class ReadonlyBox<T> {
  24   public function __construct(
  25     private readonly T $contents
  26   ) {}
  27
  28   public readonly function get(): readonly T {
  29     return readonly $this->contents;
  30   }
  31
  32   public function set(readonly T $x): void {
  33     $this->contents = $x;
  34   }
  35 }
  36
  37 <<__EntryPoint>>
  38 function main(): void {
  39   $y = new Test(new Foo());
  40   $a = readonly $y->prop;
  41   $y = new ReadonlyBox($a);
  42   $z = readonly $y->get();
  43   readonly foo($z);
  44   echo "Done\n";
  45 }