[xkbcommon] Use an integer type for modifiers bit mask.

Wander Lairson Costa wander.lairson at gmail.com
Fri Oct 4 07:53:31 PDT 2013

2013/10/4 David Herrmann <dh.herrmann at gmail.com>:
> Hi
> On Fri, Oct 4, 2013 at 2:34 PM, Daniel Stone <daniel at fooishbar.org> wrote:
>> On 4 October 2013 13:09, Wander Lairson Costa <wander.lairson at gmail.com> wrote:
>>> That's what the patch is about: avoid casts. Whenever you use a cast,
>>> you are giving up the help the compiler may give to you regarding
>>> invalid type conversions. So, I always use the rule of thumb of
>>> avoiding casts whenever I can. IMO, this is not a harmful patch and
>>> will make the C++ programmers a little bit easier.
>> I can see where it's going, but on the other hand xkb_mod_mask_t is
>> _so_ not the right type.  That's a bitmask of actual modifiers (i.e.
>> the return value), not a bitmask of components.  So it avoids the
>> cast, but also makes the API look extremely misleading, as we've
>> documented exactly what xkb_mod_mask_t is.
>> I really like the type safety aspect, so to be honest I'm just
>> inclined to make C++ wear the cast for now.
> We had a similar discussion when I pointed out that "enum" may change
> the underlying type without notice when adding new enum-values. But I
> agree with Daniel, the GCC type-safety for enums in C is a very handy
> feature. So I'm also no big fan of the patch, sorry.

We have conflictings pros and cons here, with different tradeoffs, I
perfectly understand that.

Best Regards,
Wander Lairson Costa

More information about the wayland-devel mailing list