I’m announcing the core_io and core_collections crates, bringing the IO traits and the HashMap and HashSet data structures to the
no_std world. (Note that core_collections has an optional dependency on the rand crate which poses some problems, you might want to supply your own, or follow rand PR #108)
The code in the crates is mostly just copied directly from the rust source with some straight-forward deletions. The crates have a build script that make sure that you will be using the same source that was used for the libstd version that comes with your compiler. I intend to set up some automation to automatically update the crate for every new nightly version, but for now it has to be done by hand. Ping me (or submit a PR) if you need a newer version.