error[E0308]: mismatched types --> $DIR/issue-17033.rs:2:10 | LL | (*p)(()) | ---- ^^ | | | | | expected `&mut ()`, found `()` | | help: consider mutably borrowing here: `&mut ()` | arguments to this function are incorrect error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.