error[E0308]: mismatched types
  --> $DIR/typeck.rs:9:22
   |
LL |         Ok(x) if let Err(_) = x => {},
   |                      ^^^^^^   - this expression has type `Option<bool>`
   |                      |
   |                      expected `Option<bool>`, found `Result<_, _>`
   |
   = note: expected enum `Option<bool>`
              found enum `Result<_, _>`

error[E0308]: mismatched types
  --> $DIR/typeck.rs:11:22
   |
LL |         Ok(x) if let 0 = x => {},
   |                      ^   - this expression has type `Option<bool>`
   |                      |
   |                      expected `Option<bool>`, found integer
   |
   = note: expected enum `Option<bool>`
              found type `{integer}`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0308`.