使用PHP 5.3中的命名空间自动加载？

How do you use _autoload in PHP 5.3 with namespaces? I have a main autoload function in a namespace separate from my script. I'm also calling a class with a different namespace. (It's not surprising, but) It's not finding the autoload function. Do I have to recreate the autoload function for each namespace? That seems suboptimal.How do you use _autoload in PHP 5.3 with namesp