alt Hacker NewsThanks for everything Orson! I know Clang struggled to ship improved sorts for their C++ implementation, so it's a good sign that Rust was able to ship ipnsort and driftsort without too much chaos.
Also, Lukas looked over my `misfortunate` crate (which provides "perverse" implementations of safe Rust traits) and although misfortunate isn't intended for testing he has inspired me to improve the perverse implementations of Ord, not for testing per se but to further illustrate. It occurs to me I should point anybody reading misfortunate's documentation at your/ Lukas' work in case they actually need really nasty tests not just mild perversion.
Replies
> I know Clang struggled to ship improved sorts for their C++ implementation
Clang has no built-in sorting algorithms. I imagine you're referring to the LLVM project's libc++? Though all common distributions of LLVM default to GCC's libstdc++.
Fun, but there is a mistake in https://docs.rs/misfortunate/latest/misfortunate/struct.Maxw... which claims: "yet violates the social contract of these two combined. A Maxwell is not equal to anything (even itself) but all Maxwells hash the same"
but that's not a violation of the contract, it's just a hash collision. Hash collisions are expected to happen, so HashMap and HashSet won't "misbehave seriously", they'll just be slow (linear-time lookup) and unable to remove entries.
The contract of Hash is that if two values are equal, then they hash to the same value. Which would be violated by doing the opposite of Maxwell: all values equal each other, but their hash differs (you can even make it random so it changes across calls on the same value!)