Maybe it can be more explicative and useful to learn Rust using more Rust features in those examples.
I think, for example, at binary_search.rs, which can include generics and traits (in a very simple way), to understand how/why to use them, and experiment the zero-cost abstraction feature of the Rust programming language.
For that, I propose to write multiple functions that exploit each of those features, or to exploit those features in different source code files.
Are you interested by one of those proposals?