I would love it if Rust 2018 had one way to order some numbers where NaNs and infinities are programming errors that should result in a panic.
This seems like an idiom that is a legitimate use case of rust, but we'd all have an easier life if this choice was baked into std somehow.
Impls I know of:
https://github.com/DanielKeep/rust-numeric-float
https://github.com/SergiusIW/noisy_float-rs
https://github.com/mmrath/pure_decimal
I'm sure there's more out there.