Description:
------------
While developing a NumPy equivalent for PHP (using C) I came across a limitation. I coulnd't perform arithmetic operations with objects, so a code like this is impossible (wich is possible with NumPy):

$a = CArray::fromArray($arr);
$result = $a + $a;

I was thinking about the possibility of a new magic method that would intercept the arithmetic operations:

class CArray
{
    ...

    public function __arithmetic($operator, $operand)
    {
        if($operator == PHP_ADD_OP) {
            return self::add($this, $operand);
        }
        ...
    }
}

consequently the code below would also be valid if the class were used in conjunction with __offsetGet:

$b = CArray::fromArray([]);
$a = CArray::fromArray([0, 2, 1, 0]);
$b[$a - 1];

Also, assignment magic method would be useful in some situations relative to C pointer index within PHP Objects (like a PHP Object pointing to an C array position in memory using an extension):

function test($a)
{
    $b = $a; // POINTS TO 0
    $c = $b; // POINTS TO 0
    return $c; // POINTS TO 0
}

$arr = CArray::fromArray([1, 2]);  // UUID: 0
test($arr);
// GC RUNS AND FREE $b
// $arr is not freed, but its pointer was freed with $b
// any operations with $arr will cause memory troubles

If $arr has a pointer to a C buffer and contains an __destruct method that free that buffer position, when GC runs
the code above it should cause seg faults or memory leaks. During assignment all ($a, $b, $c, $arr) got the same
values of $arr (wich contains the [1, 2] array position in memory), instead, it should be capable of "clone" this 
array to a new memory position and retrieve a new pointer, so $b, $c and $a would all be equal to $arr but in different
memory positions.

I guess __assign($value) magic method would solve this, by assigning to the object the return of this method, writing over it.

Sorry about my bad english, I hope you guys got the idea.