error[E0600]: cannot apply unary operator `-` to type `bool`
  --> $DIR/unop-neg-bool.rs:2:5
   |
LL |     -true; //~ ERROR cannot apply unary operator `-` to type `bool`
   |     ^^^^^ 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`.