I was just reveiwing @briansmith’s rand definition in ring, and quite like it. This looks like a really good, minimal, and correct foundation. Though I think we want to give users more conveniences than that. The method that most casual end users want is more like the existing rand crate’s polymorphic random method.
I’d personally feel really good about paring rand way back to be more like ring’s rand with some conveniences. Leaving most of the other matters touched on by rand today to future work in other crates.