Remove \Drupal\Component\Utility\MapArray

Correction:

https://bugs.php.net/bug.php?id=34857 was fixed around the time of PHP 5.1, but is only available since PHP 5.4:

http://php.net/manual/en/function.array-combine.php#refsect1-function.ar...

5.4.0 Previous versions issued E_WARNING and returned FALSE for empty arrays.

So once #2152073: Bump Drupal core's PHP requirement to 5.4.2 is possible and done, we can eliminate MapArray entirely.

The optional $callback support is completely obsolete since PHP 5.3 already, because that's the same as:

$result = array_map(function ($value) {
  return $value * 2;
}, array_combine($list, $list));

Actually, this removes the @deprecated function, too. :)

wrong order of arguments:)

No, worries.. messing up order of arguments in PHP is a common fail..php--

Wow, this looks awesome - great job!

I guess we need to prepare a draft change notice for the API change of removing drupal_map_assoc(), describing how to achieve the same with native PHP (as demonstrated in this patch).

draft change record: https://drupal.org/node/2207453

That PHP bug isn't the reason we have MapArray, this is. Let's see if that's still valid first and whether we care or not.

https://drupal.org/comment/913381#comment-913381

Ignore me, I had another issue that got reverted, but the one linked above got in. So yes indeed that's the only reason, and we're on 5.4 now.

Committed/pushed to 8.x, thanks! Nice to see us finally get rid of this after trying six years ago.

Fyi: drupal_map_assoc is used by drush currently, so if you'll have some drush problems with current d8 HEAD until its fixed.