No Duplicate Keys In Array

Disallow the creation of duplicate keys in literal arrays.

This is useless as the second defined key will overwrite the first silently.

Rule Details

This rule require that every array() call has unique keys. The following is wrong.

<?php
$a = array(1 => 'a',
			 2 => 'b',
			 3 => 'c',
			 1 => 'a' // double definition
			 );
?>

The following patterns are considered OK :

<?php
$a = array(1 => 'a',
			 2 => 'b',
			 3 => 'c',
			 );

$a[1] = 'a'; // this doesn't belong to the literal definition anymore

?>