Author: Stan Eisenstat
Subject: Re: [Cs223] checking failure of dequeu functions
Date: Monday, 23 Mar 2020, 07:10:59

    > Message Posted By: Unknown
    >
    > must we check for failure each time we use addD(), remD(), etc?

Yes.  As stated in the specification:

  1. If POS and/or LEN is not a nonempty sequence of digits, or a file does not
     exist, OR ONE OF THE DEQUE FUNCTIONS REPORTS AN UNEXPECTED ERROR (e.g.,
     createD() returns false), then Qsort writes a one-line error message to the
     standard error and exits.

(emphasis added).

--Stan-