Am 10.08.23 um 03:00 schrieb Junio C Hamano:
> Jeff King <peff@xxxxxxxx> writes:
>
>> int my_foo;
>> ...
>> OPT_CALLBACK('f', "foo", int, &my_foo, ...etc);
>>
>> Not great, but it might not be _too_ bad given that most helpers like
>> OPT_BOOL() can just say "int" behind the scenes.
>>
>> That said, I don't recall these void pointers being a large source of
>> errors in the past. So while it's a fun type-system puzzle, the
>> effort/reward ratio might not be favorable.
I have vague memories of changing a callback from using a string_list
to a strset (or whatever) and getting crashes out of some other callers
that used it non-obviously via some macro. A compile-time check would
have helped me.
> I tend to agree on both counts, it is a fun puzzle, and it probably
> is not going to give us sufficient reward. The fact that "int" and
> typeof(my_foo) need to be manually kept straight defeats the "type
> safety" justification for this mental exercise.
The many-pointers idea is a bit silly, admittedly.
Having to declare a type manually is how most of C's type safety works,
though, so a certain amount of that is unavoidable.
typeof (along with typeof_unqual) is nice, but I guess it will take a
few years (or decades?) before we can expect it to be supported by all
relevant platforms.
The typed-callback-with-void-wrapper idea seems promising. Let's see
if we can get it into usable shape.
René
