Function with_finally 

pub fn with_finally<TASK, T, E, FINALLY, FT, FE>(
    finally: FINALLY,
    task: TASK,
) -> Result<T, E>
where
    TASK: UnwindSafe + FnOnce() -> Result<T, E>,
    FINALLY: UnwindSafe + FnOnce() -> Result<FT, FE>,
    E: Display,
    FE: Display + Into<E>,

Perform task. On success, error, or panic, perform finally and return the original success or error, or continue to panic.

This is resilient to errors and panics in finally too. If task finishes successfully, errors and panics from finally are propagated. However, errors and panics from task will be propagated in preference to those coming out of finally – but they will be logged.