title: php closures: why the 'static' in the anonymous function declaration when binding to static class?
body: <p>The example in the php documentation on <code>Closure::bind</code> include <code>static</code> on the anonymous function declaration. why? I can't find the difference if it is removed.</p>
  
  <p><strong>with</strong>:</p>
  
  <pre><code>class A {
      private static $sfoo = 1;
  }
  $cl1 = static function() { // notice the "static"
      return self::$sfoo;
  };
  $bcl1 = Closure::bind($cl1, null, 'A');
  echo $bcl1(); // output: 1
  </code></pre>
  
  <p><strong>without</strong>:</p>
  
  <pre><code>class A {
      private static $sfoo = 1;
  }
  $cl1 = function() {
      return self::$sfoo;
  };
  $bcl1 = Closure::bind($cl1, null, 'A');
  echo $bcl1(); // output: 1
  </code></pre>