error[E0308]: `match` arms have incompatible types --> $DIR/closure-no-fn-4.rs:5:18 | LL | let _: fn(usize) -> usize = match true { | _________________________________- LL | | true => |a| a + 1, | | --------- this is found to be of type `fn(usize) -> usize` LL | | false => |a| a - b, | | ^^^^^^^^^ expected fn pointer, found closure LL | | LL | | }; | |_____- `match` arms have incompatible types | = note: expected fn pointer `fn(usize) -> usize` found closure `{closure@$DIR/closure-no-fn-4.rs:5:18: 5:21}` note: closures can only be coerced to `fn` types if they do not capture any variables --> $DIR/closure-no-fn-4.rs:5:26 | LL | false => |a| a - b, | ^ `b` captured here error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0308`.