Description:
------------
The anonymous functions wouldn't really be complete without dereferencing, making 
it easier for developers to split their code up into chunks, and having one return  
value. Database calls that are only going to be called once for example, but need 
to be stored in an array. There's no point making a whole function for it and no 
point setting it to a variable to be run once.

Test script:
---------------
$my_array = [
    'key_1' => function() {
         return mt_rand();
    }(),

    'database' => function() {
        $db  = new PDO("mysql:host=127.0.0.1; port=3306;", "root", "");
        $sth = $db->prepare("SELECT * FROM `users` WHERE `username`=? LIMIT 1");
        $sth->bindParam(1, 'Test');
        $sth->execute();
        return $sth->fetch(PDO::FETCH_ASSOC);
    }()
];

Expected result:
----------------
An array with two values, a random value on 'key_1' and an associative array on 
'database'.

Actual result:
--------------
Parse error: syntax error, unexpected '(', expecting ']' in php shell code on line 
4

When leaving out the parentheses; two closure classes.