array_unique optional compare-callback proposal

Hello, I would like to propose addition of a third (optional) argument for array_unique which will be callback for comparing elements. There's a plenty of usecases for this. For example, what I've been dealing with can be described like so: <?php $obj1 = new EntityName("asd"); $obj2 = new EntityName("qwe"); $a = [new EntityWrapper($obj1, ...), new EntityWrapper($obj2, ...), new EntityWrapper($obj1, ...)]; // now it can be solved like so: $newArray = []; foreach ($a as $e) {

    $newArray[$e->getWrappedObject()->getIdentity()] = $e;

} // but with this patch it can be solved with array_unique: $newArray = array_unique($a, SORT_USERDEFINED, function ($a, $b) {

    return $a->getWrappedObject()->getIdentity() - $b->getWrappedObject()->getIdentity();

}); Actually my problem was a little different but you get the idea... And I think there will be even more usecases for this. Here's a patch for master branch with implementation of this proposal: https://gist.github.com/nikita2206/7354392