Am I allowed to use a custom HashMap for the game, or am I required to use the one in std::collections? My understanding is that it's the latter, and so that penalizes Rust or any other language that includes a map in their standard library.
In fact, the current Rust k-nucleotide DOES use a custom Hash function with a library Hash map.
No one is allowed to -- in your words -- "write an entirely custom [hashmap] just for the benchmark".
(This was all discussed to death, in early December on https://www.reddit.com/r/rust/ ).
Meanwhile, from the task description: Please don't implement your own custom "hash table" - it will not be accepted.
If you want an additional Rust hashmap implementation then you need to persuade the Rust community to provide one in std::collections.
No one is allowed to -- in your words -- "write an entirely custom [hashmap] just for the benchmark".
Again, this means that for Rust, it _has_ to be in the standard library. But C doesn't have one in the standard library. So C gets to write their own, and Rust doesn't.
> Since C doesn't have a standard library hashmap, you can write an entirely custom one just for the benchmark.
NOT TRUE!
#315195 states the opposite!
"k-nucleotide will explicitly require built-in / library HashMap"