<?php class Foo { public function __construct($a) { $this->a = $a; } public function __call($closure, $args) { return call_user_func_array($this->{$closure}->bindTo($this),$args); } } $foo = new Foo(100); $foo->add = function ($b) { $this->a += $b; }; $foo->add(50); echo $foo->a;