error[E0308]: mismatched types --> $DIR/closure-reform-bad.rs:11:15 | LL | let f = |s: &str| println!("{}{}", s, string); | --------- the found closure LL | call_bare(f) | --------- ^ expected fn pointer, found closure | | | arguments to this function are incorrect | = note: expected fn pointer `for<'r> fn(&'r str)` found closure `[closure@$DIR/closure-reform-bad.rs:10:13: 10:22]` note: closures can only be coerced to `fn` types if they do not capture any variables --> $DIR/closure-reform-bad.rs:10:43 | LL | let f = |s: &str| println!("{}{}", s, string); | ^^^^^^ `string` captured here note: function defined here --> $DIR/closure-reform-bad.rs:4:4 | LL | fn call_bare(f: fn(&str)) { | ^^^^^^^^^ ----------- error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.