[listeria]

may I introduce you to the nodiscard attribute[1]?

  enum (class)? [[nodiscard]] Error {
    Ok,
    NoMem,
    ...
  };

[1]: https://en.cppreference.com/w/cpp/language/attributes/nodisc...

[drysine]

   C attribute: nodiscard (since C23)

[1] https://en.cppreference.com/w/c/language/attributes/nodiscar...

[senderista]

FWIW I’ve been using warn_unused_result in both gcc and clang since about 2020.