error[E0599]: no method named `closure` found for struct `Obj` in the current scope --> $DIR/issue-18343.rs:7:7 | LL | struct Obj where F: FnMut() -> u32 { | ------------------------------------- method `closure` not found for this ... LL | o.closure(); | ^^^^^^^ field, not a method | help: to call the function stored in `closure`, surround the field access with parentheses | LL | (o.closure)(); | ^ ^ error: aborting due to previous error For more information about this error, try `rustc --explain E0599`.