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Date: Thu, 07 Nov 2013 17:24:44 +0400
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Subject: array_unique optional compare-callback proposal
From: inefedor@gmail.com ("Nikita Nefedov")

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