There is a new blog post on Swift.org titled "Standard Library Preview Package" that talks about the new preview package mechanism for forthcoming Standard Library changes:
The post is written by @nnnnnnnn . Please feel free to ask questions about the blog post here!
I've posted this before, in the thread about making swift.org more useful, but it would be great if the clickjacking on the website that stops command-clicking links from working was removed or fixed.
Great feature 
Here is my question:
If the implementation of a proposal requires to access some internal APIs in Foundation or Standard library, can we achieve that with the Standard Library Preview Package?
If so, could you please share one example?