function changeValueOfReference(&$input)
{
    echo '----> changeValueOfReference ' . PHP_EOL;
    _mem();
    xdebug_debug_zval_stdout('input');
    $input = sizeof($input);
    _mem();
    // cant no use _var for input since function scope will change
    xdebug_debug_zval_stdout('input');
    echo '<---- ' . PHP_EOL;
}
    echo " --- in anon function ----" . PHP_EOL;
    _mem();
    echo " -------------------------" . PHP_EOL;
};
_mem();
_step("Anon function call");
$anon();
_mem();
$anonAlias = $anon;
_step("Anon function call again via alias");
$anonAlias();
_mem();
_step("Anon function remove");
unset($anon);
_mem();
_step("Anon function alias remove");
unset($anonAlias);
_mem();
$loop = 5;
for ($i = 1; $i <= $loop; $i++) {
    _step("Loop [{$i}/{$loop}] anon function define");
    $anon = function () {
        static $static = 0;
        $static = _data(1);
        $dynamic = _data(1);
    };
    _mem();
    _step("Loop [{$i}/{$loop}] anon function call [loop]");
    $anon();
    _mem();
}