Description:
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At the moment, you can't do things like:

$GLOBALS === $GLOBALS;

or

$a = array('a' => &$a); $a === $a['a'];

both causes fatal error claiming too deep nesting level.

I find it rather strange that you can use references, but you can't test if something is referencing the same thing or not...

It would be nice to have some ==== or is_same(&$a,&$b) function which would just do a lookup in the symbol table and if the two variables referencing the same thing it would return true, false otherwise.


Reproduce code:
---------------
$a = is_same($GLOBALS,$GLOBALS);

$x = array('x' => &$x);
$b = is_same($x, $x['x']);

$x1 = array('c' => &$x1);
$x2 = array('c' => &$x2); //same layout, but not the same variable;
$c = is_same($x1,$x2);

$y1 = "test";
$y2 = $y1; /* plain assignement, maybe same till y1 or y2 not changed, but is_same() shouldn't get affected by optimization behaviour */
$d = is_same($y1,$y2);

$z1 = "test2";
$z2 = &$z1; //or $z2 =& $z1;
$e = is_same($z1,$z2);

Expected result:
----------------
$a === true;
$b === true;
$c === false;
$d === false;
$e === true;



Actual result:
--------------
No way to do this ATM (AFAIK). But please tell me if i didn't read the documentation properly...