Description:
------------
If a class defines a __equals($other) function, invoke that function on
object comparison. Example:

==========================
class MyClass {
    public function __construct($value) {
        $this->value = $value;
    }

    /**
     * This function should be invoked on object
     * comparison with == or != operators.
     */
    public function __equals($other) {
        if ($other instanceof MyClass) {
            return ((int)$this->value
                   == (int)$other->value);
        } else {
            return false;
        }
    }

    private $value;
}

$a = new MyClass(3.14);
$b = new MyClass(3.13);

if ($a == $b) {
    echo '$a equals $b';
}
==========================

The comparison of $a and $b should result in the invokation of __equals
function of MyClass. The same should apply to the != (not equals)
operator.

If at all then we should be able to do all comparisons directly by
__compare($other, $operator) where operator is one of {<,<=,==,!=,>,>=}
or by another method __less() which performs a < test so that __less()
and __equals() can be used to emulate all other tests.

Would love this feature! Java implements this through:

class Object {
   boolean equals(Object o);
}

So you could either make all user-defined objects include a simple
equals() function [and similarly, identical()].

Or perhaps, develop the aforementioned magic __equals() [and
__identical()] functions. (As well as __less())

We're not going to have more magic then there already is; those things
are going to be to complicated and confusing (See the __string()) issue.