How to pass object context to an anonymous function?

Is there a way of passing object context to an anonymous function without passing $this as an argument?

class Foo {
    function bar() {
        $this->baz = 2;
        # Fatal error: Using $this when not in object context
        $echo_baz = function() { echo $this->baz; };
        $echo_baz();
    }
}
$f = new Foo();
$f->bar();