[carlmr]

On your example, without reading into the implementation, I'm wondering if the comment is wrong, or if the comment is telling us about a hidden default, but then what does the 2 mean.

    // Create an LRU cache with a capacity of 100 entries
    let mut cache = LRUKCache::new(2);

Why 100? Why not 2?

[touisteur]

Another time I wish rust had named parameters. For reading code without an IDE (which is a lot of the experience in discovering a library, learning, navigating in code on github...) it would be useful.

[carlmr]

I think so, too, it's beautifully designed in many ways, but this seems like an oversight.

[failsafe]

derp, It should be LRU instead of LRU-K.