--TEST--
callback function is a closure
--SKIPIF--
<?php if (!extension_loaded("filter")) die("skip"); ?>
--FILE--
<?php
$callback = function ($var) {
    return $var;
};
$var = "test";
var_dump(filter_var($var, FILTER_CALLBACK, array('options'=> $callback)));
?>
--EXPECT--
string(4) "test"