empty value

在对echsop进行二开的时候，我很简单地写了一句；

	$shop_style = empty(intval($_POST['shop_style'])) ? 1:intval($_POST['shop_style']);

结果一打开页面就报错：

Fatal error: Can't use function return value in write context in ...index.php on line 503

怎么看这代码都没有问题呀，上网搜索才发现，对于empty()函数，有如下描述

Note: empty() only checks variables as anything else will result in a parse error. In other words, the following will not work: empty(trim($name)).

empty() 只检测变量，检测任何非变量的东西都将导致解析错误!

所以说上面那句正确的写法应该是

	$shop_style = empty($_POST['shop_style']) ? 1:intval($_POST['shop_style']);