title: How to declare String only in PHP method argument?
body: <p>I'm trying to use this method :</p>
  
  <pre><code>public function setMessage(string $message){
      $this-&gt;message = $message;
  }
  </code></pre>
  
  <p>Then I get this error : </p>
  
  <blockquote>
    <p>Catchable fatal error: Argument 1 passed to notifier::setMessage()
    must be an instance of string, string given</p>
  </blockquote>
  
  <p>Apparently PHP is interpreting <code>string</code> as class name. Is there a look like solution to make that kind of declaration ?</p>