Description:
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in foreach loop, if i try to use keys as a reference, i'll get "Fatal error: Key element cannot be a reference". my question is why not? can Zend developers add the possibility of key element reference in the sixth PHP version??

Reproduce code:
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     foreach($arr as &$key => $val)
     {
      ...
     }

Expected result:
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change keys inside the foreach loop

Actual result:
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Fatal error: Key element cannot be a reference