error[E0412]: cannot find type `n` in this scope --> $DIR/issue-90871.rs:2:8 | LL | 2: n([u8; || 1]) | ^ expecting a type here because of type ascription error[E0308]: mismatched types --> $DIR/issue-90871.rs:2:15 | LL | 2: n([u8; || 1]) | ^^^^ expected `usize`, found closure | = note: expected type `usize` found closure `[closure@$DIR/issue-90871.rs:2:15: 2:17]` help: use parentheses to call this closure | LL | 2: n([u8; (|| 1)()]) | + +++ error: aborting due to 2 previous errors Some errors have detailed explanations: E0308, E0412. For more information about an error, try `rustc --explain E0308`.