error[E0621]: explicit lifetime required in the type of `get` --> $DIR/variance-trait-matching.rs:24:5 | LL | fn get<'a, G>(get: &G) -> i32 | -- help: add explicit lifetime `'a` to the type of `get`: `&'a G` ... LL | pick(get, &22) | ^^^^^^^^^^^^^^ lifetime `'a` required error: aborting due to previous error For more information about this error, try `rustc --explain E0621`.