error: lifetime may not live long enough --> $DIR/issue-16922.rs:4:5 | LL | fn foo(value: &T) -> Box { | - let's call the lifetime of this reference `'1` LL | Box::new(value) as Box | ^^^^^^^^^^^^^^^ cast requires that `'1` must outlive `'static` | help: to declare that the trait object captures data from argument `value`, you can add an explicit `'_` lifetime bound | LL | fn foo(value: &T) -> Box { | ++++ error: aborting due to previous error