hphp/hack/test/typecheck/stringish.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 CExplicit implements Stringish {
  13   public function __toString(): string {
  14     return __CLASS__;
  15   }
  16 }
  17
  18 class CImplicit {
  19   public function __toString(): string {
  20     return __CLASS__;
  21   }
  22 }
  23
  24 interface IImplicit {
  25   public function __toString(): string;
  26 }
  27
  28 function f1(Stringish $x): string {
  29   return __FUNCTION__.': '.$x;
  30 }
  31
  32 function f2(): void {
  33   f1("a boring string");
  34   $x = "dynamic ";
  35   $x .= "string";
  36   f1($x);
  37   $explicit = new CExplicit();
  38   f1($explicit);
  39   $implicit = new CImplicit();
  40   f1($implicit);
  41 }
  42
  43 function f3(IImplicit $i): void {
  44   f1($i);
  45 }
  46
  47 trait TStringish {
  48   public function __toString(): string {
  49     return __TRAIT__;
  50   }
  51
  52   private function foo(): void {
  53     echo 'foo'.$this;
  54   }
  55 }
  56
  57 trait TReq {
  58   require implements Stringish;
  59
  60   private function foo(): void {
  61     echo 'foo'.$this;
  62   }
  63 }