Re: [using gcc book] ch10.11 Certain Changes We Don't Want to Make

["Zack Weinberg" <zack at codesourcery dot com>]

Chris Devers <cdevers@pobox.com> writes:

> In section 10.11, "Certain Changes We Don't Want to Make"
> we have the following paragraph:
>
>   * Warning when a non-void function value is ignored.
>
>     Coming as I do from a Lisp background, I balk at the idea that
>     there is something dangerous about discarding a value. There
>     are functions that return values which some callers may find
>     useful; it makes no sense to clutter the program with a cast
>     to void whenever the value isn't useful.
>
> There's just a bit more axe-grinding from the MIT alum that wrote this
> than is strictly necessary, I think :)

Agree.  I'm not even sure such a warning would be rejected today, if
someone submitted a clean patch for it.  I doubt we would put it into
-Wall, but having the option seems fair to me.

...
> Here's what I've got for a replacement:
>
>     Think carefully before discarding values.  There are functions
>     that return values which some callers may find useful, but it
>     makes no sense to clutter the program with a cast to void
>     whenever the value isn't useful.
>
> But even that is more "preachy" than I feel is appropriate.
>
> Would anyone care to suggest improvements?

Well, the paragraph does need to justify the policy decision not to
include this feature, so:

   * Warning when a non-void function value is ignored.

     We feel that there are legitimate reasons to ignore function
     return values, and that writing @code{(void)} before every
     function call whose result is intentionally ignored makes the
     program harder to read for little benefit.

zw