Thanks. Sorry, I think this one was just my inattentiveness.

The function signature of the starter code shows that it expects Option<(u64, u32)>. To keep the description clean and easily maintainable, a lot of language-specific features are either inferred from the description or gleaned from the starter code or sample tests. All languages share the same description, the only way around it is to have a very long description that specifies everything for every language or to use a somewhat clunky method of showing different text blocks for different languages, which is a headache for kata authors to maintain. In this case, I think the function signature should be enough to let you know what you're supposed to return.

Rust: Clarify Output Type of Function

The Rust version of this kata does not specify that the output should be an Option<(u64, u32)>, and this causes a few cryptic error messages from the compiler in random testing depending on the output variant. When an Option<(u64, u64)> is used, there is an error regarding the use of .pow() on a u64, but no indication that this is related to the kata.

Almost did the same thing...but I changed the trait bounds on array_diff to also require that T implement the Copy trait.
Then I used iter and copied instead of just using into_iter like I should have...because I initially misspelled into_iter while trying this exact thing :P