error[E0600]: cannot apply unary operator `-` to type `bool` --> $DIR/unop-neg-bool.rs:2:5 | LL | -true; | ^^^^^ cannot apply unary operator `-` | = note: an implementation of `std::ops::Neg` might be missing for `bool` error: aborting due to previous error For more information about this error, try `rustc --explain E0600`.