Description:
------------
using return value of implode() as empty() param causes "Fatal error: Can't use function return value in write context"
empty(implode($arr))

Test script:
---------------
<?php
$foo = array('b','a','r');
if (empty(implode('', $foo)
{
    echo 'ok';
}
else
{
    echo 'not ok';
}
?> 

Expected result:
----------------
'ok' or 'not ok' string, not fatal error :)

Actual result:
--------------
Fatal error: Can't use function return value in write context