hphp/hack/test/typecheck/readonly/list_assign.php

   1 <?hh
   2 <<file:__EnableUnstableFeatures('readonly')>>
   3 class Bar {}
   4 class Foo {
   5   public int $prop;
   6   public readonly Bar $ro;
   7   public Bar $not_ro;
   8   public function __construct() {
   9     $this->prop = 1;
  10     $this->ro = new Bar();
  11     $this->not_ro = new Bar();
  12   }
  13   public function set(int $y) : void {
  14     $this->prop = $y;
  15   }
  16
  17   public readonly function get() : int {
  18     return 4;
  19   }
  20 }
  21
  22
  23 function test(readonly (Foo, Foo) $x): void {
  24   list($a, $b) = $x;
  25   $a->prop = 4; // error $a is readonly
  26   $b->prop = 4; // error $b is readonly
  27 }