title: PHP Call to undefined function with NameSpace
body: <p>I start coding with use "namespace".</p>
  
  <p><strong>Core.php:</strong></p>
  
  <pre><code>namespace Language;
      class LanguageCore {
          private $langCode = "pl";
          private $language;
          public function __construct(){
              if(file_exists("lang/".substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2).".php"))
                  $this-&gt;langCode = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
              require_once "lang/".$this-&gt;langCode.".php";
              $this-&gt;language = new language();
          }
          public function gt($index = null)
          {
              return "its work";
          }
      }
  </code></pre>
  
  <p>and one work very well</p>
  
  <p><strong>Index.php:</strong></p>
  
  <pre><code>  require_once 'core.php';
    use Language\LanguageCore as Lang;
  
    $lang = new Lang();
    echo $lang-&gt;gt(); // return "its work"
  </code></pre>
  
  <p>but when I tried to add "use function" I had a fatal error</p>
  
  <pre><code>  require_once 'core.php';
    use Language\LanguageCore as Lang;
    use function Language\LanguageCore\gt as _;
  
    $lang = new Lang();
    echo _(); // return error
  </code></pre>
  
  <p>error message:</p>
  
  <pre><code>Fatal error:  Uncaught Error: Call to undefined function Language\LanguageCore\gt()
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>regards!</p>
  
  <p>EDIT:
  I need to have this function in a class because I'm using a class variable in this function.</p>