Detecting whether a PHP variable is a reference / referenced

Question

Is there a way in PHP to determine whether a given variable is a reference to another variable and / or referenced by another variable? I appreciate that it might not be po

Answer 1

Edit: It seems I've answered the question 'is it possible to check if two variables are referencing same value in memory' not the actual question asked. :P

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As far as 'plain' variables go the answer is 'no'.

As far as objects go - maybe.

All objects are by default handled by references. Also each object has it's serial number which you can see when you var_dump() it.

>> class a {};
>> $a = new a();
>> var_dump($a);

object(a)#12 (0) {
}

If you could get somehow to this #, you could effectively compare it for two variables, and see if they point to the same object. The question is how to get this number. var_export() does not return it. I don't see snything in Reflection classes that would get it either.

One thing that comes to my mind is using output buffering + regex