Illegal Eq derive in an enum with Option<f64> #103157
Description
I tried this code:
#[derive(PartialEq, Eq)] pub enum Value { Boolean(Option<bool>), Float(Option<f64>), } fn main() { let a = Value::Float(Some(f64::NAN)); // Eq should always have a == a // https://doc.rust-lang.org/std/cmp/trait.Eq.html assert!(a == a); }I expected to see this happen: code fails to compile.
Instead, this happened: code compiles, and assertion fails.
Changing order of enum variants to make Float go first fixes the issue:
// error[E0277] the trait bound `f64: Eq` is not satisfied #[derive(PartialEq, Eq)] -- in this derive macro expansion pub enum Value { Float(Option<f64>), Boolean(Option<bool>), } Meta
rustc --version --verbose:
rustc 1.64.0 (a55dd71d5 2022-09-19) binary: rustc commit-hash: a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52 commit-date: 2022-09-19 host: aarch64-apple-darwin release: 1.64.0 LLVM version: 14.0.6 It's reproducible in Playground in Stable, Beta and Nightly.