This crate provides various "Frozen" collections.
These are append-only collections where references to entries can be held
on to even across insertions. This is safe because these collections only
support storing data that's present behind some indirection -- i.e.
Box<T>, etc, and they only yield references to the data behind the
The typical use case is having a global cache of strings or other data which the rest of the program borrows from.
This module is experimental