In all fairness I have yet to see a language with an awesome builtin collections library that meets everyones needs (and I use JDK collections all the time....

In all fairness I have yet to see a language with an awesome builtin collections library that meets everyones needs (and I use JDK collections all the time.... it took a long time to get where it is and still is sort of ok). If you know of a language that does please chime in. The big thing I missed in my limited playing around with Rust is more types of queues. This is in large part because I was attacking Rust in a similar way to Java. Because of its lack of other concurrency models other than threads I was resorting to queues (I'm sure there are more "reactive-like" libraries now). Overall I can't decide if a better approach might be to let library writers work on adding more structures instead of a batteries included approach. Maybe just have the traits included and thats it.