error[E0308]: `if let` arms have incompatible types
  --> $DIR/if-let-arm-types.rs:12:5
   |
LL | /     if let Some(b) = None { //~ ERROR: `if let` arms have incompatible types
LL | |         //~^ expected (), found integral variable
LL | |         //~| expected type `()`
LL | |         //~| found type `{integer}`
...  |
LL | |         1
LL | |     };
   | |_____^ expected (), found integral variable
   |
   = note: expected type `()`
              found type `{integer}`
note: `if let` arm with an incompatible type
  --> $DIR/if-let-arm-types.rs:17:12
   |
LL |       } else {
   |  ____________^
LL | |         1
LL | |     };
   | |_____^

error: aborting due to previous error

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