Description:
------------
It's already possible to have arrays that represent callable methods (either static or instance), and 5.3's closures offer a third type of "callable" function.

But the $foo() syntax that facilitates calling that callable function still requires $foo to contain a string.

Since in general one cannot know in advance just what type of callable the value of $foo actually is, and when one does know it's often NOT a string, it's necessary to forego the syntax and rely on call_user_func($foo).

What would be nice is if $foo() also worked in the cases where $foo was a callable array or Closure object. call_user_func() itself would largely be relegated to the status of "function equivalent should you need it" and complement to call_user_func_array().

Reproduce code:
---------------
<?php
// For 5.2.x as well.
class Thing {
    static function DoesStuff() {
        echo 'Hello, World';
    }
}

$f = array('Thing', 'DoesStuff');

$f();
?>

Expected result:
----------------
Hello, World

Actual result:
--------------
Fatal error: Function name must be a string in C:\test.php on line 11