Generics proposal

Hello, list. I want to propose generics. For those, who don't know what it is, here's example: say we have a Comment class, that has a method getBody. Also we have Collection class, that implements Traversable. Now, if I want to validate all insertions into collection of comments, I would need to create CommentCollection class, extend it from Collection, and override all the methods that are dealing with adding new elements to collection. Moreover, I can't have any hints from my IDE about type of collection's elements, so if I'll have code like this: foreach ($commentCollection as $comment) { $comment->getBody(); } There will be no way for IDE to know, of what type that object will be. But there's how I could solve my problem with generics: class Collection<T> implements Traversable { ... public function add(T $element){} } $collection = new Collection<Comment>(); $collection->add(new Comment()); $collection->add("that will be error"); Actually, that's, again, all about type hinting. If we went so far with scalar type hinting, then generics would also be a good addition. So, what you think?