error[E0597]: `c` does not live long enough --> $DIR/regionck-unboxed-closure-lifetimes.rs:8:21 | LL | let c_ref = &c; | ^^ borrowed value does not live long enough ... LL | } | - `c` dropped here while still borrowed LL | f.use_mut(); | ----------- borrow later used here error: aborting due to previous error For more information about this error, try `rustc --explain E0597`.