If you try to use an operator on a type that doesn't implement it, the error include an note similar to this one: ``` note: an implementation of `std::ops::Add` might be missing for `Foo` ``` But for three operator, this note is missing: - `^`, `BitXor` - `-`, `Neg` (the *unary* negation) - `!`, `Not` This note is also missing for all the `*Assign` version of the operators. I've made a minimal example with the playground: https://play.rust-lang.org/?gist=1df2a3964559faed35efb8427d9c3608&version=nightly