Not quite. Lifetime annotations prevent you from accidentally using references after the value they refer to has been freed. They track how long things will liv

Not quite. Lifetime annotations prevent you from accidentally using references after the value they refer to has been freed. They track how long things will live, instead of defining how long they will live. Basically they turn use-after-free errors into compile errors. (I'm using 'free' here to mean cleaned up in general. Lifetimes can track stack values.)