Description:
------------
According to http://ca.php.net/manual/en/language.references.pass.php :

The following things can be passed by reference:

    Variables, i.e. foo($a)
    New statements, i.e. foo(new foobar())

    References returned from functions, i.e.:
[...]

No other expressions should be passed by reference, as the result is undefined.


This appears to be inexact. Elements of array variables can apparently also be passed by reference, unless this works by chance.

Test script:
---------------
<?php
function two(&$int) {
	$int = 2;
}

$a = array(1);
two($a[0]);
var_dump($a);


Actual result:
--------------
array(1) { [0]=> int(2) }