error[E0308]: mismatched types
  --> $DIR/keyword-false-as-identifier.rs:12:9
   |
LL |     let false = 22; //~ error: mismatched types
   |         ^^^^^ expected integral variable, found bool
   |
   = note: expected type `{integer}`
              found type `bool`

error: aborting due to previous error

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