Re: RFC: warnings on ignoring return value on some list operations

[Kalle Vahlman <kalle vahlman gmail com>]

2005/11/24, Tim Janik <timj imendio com>:
> On Thu, 24 Nov 2005, Owen Taylor wrote:
>
> > if (head) {
> >    g_list_append(tail, new);
> >    tail = tail->next;
> > } else {
> >    head = tail = g_list_append(null, new);
> > }
> >
> > strikes me as acceptable code, and I know there are some examples like this
> > in GTK+. Maybe the gain is worth the pain ... unless someone is compiling
> > production code with -Werror it isn't going to *break* a build, and there
> > is no bin-compat issue. But it's definitely a compatibility break of some
> > sort.
>
> i think one can argue both ways here, in the above code, i'd still write
> head = g_list_append (tail, new); and recommend that people also do that,
> because a) code is duplicated so often and this easily introduces errors
> in another context, and b) i'd like to think of the list API as something
> where i'm not allowed to ignore return values to avoid mistakes ;)

Append and perpend already have a big fat NOTE stating:

"The return value is the new start of the list, which may have
changed, so make sure you store the new value."

so I would consider anyone not doing it misusing the API. Thus this
move would be just a case of enforcing correct API usage (a very wise
move if you ask me). Specially since it's compile-time only.

--
Kalle Vahlman, zuh iki fi
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