error: unreachable pattern
  --> $DIR/unreachable.rs:15:9
   |
LL |         Err(!),
   |         ^^^^^^-
   |         |
   |         matches no values because `Void` is uninhabited
   |         help: remove the match arm
   |
   = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types
note: the lint level is defined here
  --> $DIR/unreachable.rs:5:9
   |
LL | #![deny(unreachable_patterns)]
   |         ^^^^^^^^^^^^^^^^^^^^

error: unreachable pattern
  --> $DIR/unreachable.rs:18:19
   |
LL |     let (Ok(_x) | Err(!)) = res_void;
   |                   ^^^^^^ matches no values because `Void` is uninhabited
   |
   = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types

error: unreachable pattern
  --> $DIR/unreachable.rs:20:12
   |
LL |     if let Err(!) = res_void {}
   |            ^^^^^^ matches no values because `Void` is uninhabited
   |
   = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types

error: unreachable pattern
  --> $DIR/unreachable.rs:22:24
   |
LL |     if let (Ok(true) | Err(!)) = res_void {}
   |                        ^^^^^^ matches no values because `Void` is uninhabited
   |
   = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types

error: unreachable pattern
  --> $DIR/unreachable.rs:24:23
   |
LL |     for (Ok(mut _x) | Err(!)) in [res_void] {}
   |                       ^^^^^^ matches no values because `Void` is uninhabited
   |
   = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types

error: unreachable pattern
  --> $DIR/unreachable.rs:28:18
   |
LL | fn foo((Ok(_x) | Err(!)): Result<bool, Void>) {}
   |                  ^^^^^^ matches no values because `Void` is uninhabited
   |
   = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types

error: aborting due to 6 previous errors