You cannot write a type which conditionally implements Drop: https://play.rust-lang.org/?version=stable&mode=debug&editio...

    struct Q<T>(Option<T>);

    impl<T: 'static> Drop for Q<T> {
        fn drop(&mut self) {}
    }


    error[E0367]: `Drop` impl requires `T: 'static` but the struct it is implemented for does not
     --> src/main.rs:3:9
      |
    3 | impl<T: 'static> Drop for Q<T> {
      |         ^^^^^^^
      |
    note: the implementor must specify the same requirement
     --> src/main.rs:1:1
      |
    1 | struct Q<T>(Option<T>);
      | ^^^^^^^^^^^