[Development] Changed enum property behaviour in Qt v6.8

[Phil Thompson]

Yes, that's the change - commenting out the new test fixes the problem.

I am dynamically building the meta-object. You don't really build an 
enum, you just provide a description of it to the meta-object. It would 
be nice to be able to register an enum with the meta-type system 
dynamically.

Phil

On 03/10/2024 12:51, Mårten Nordheim wrote:
> Hello!
> 
> Do you mean this change? 
> https://codereview.qt-project.org/c/qt/qtbase/+/559265
> 
> If so, my bad!
> My motivation is described in the commit, but basically QtProtobuf is
> quite heavy on
> QMetaProperty usage, and trying to resolve the 'menum' was quite a
> bottleneck for
> properties that were not known as enums in the metatype system (and 
> thus treated
> differently).
> 
> When you say you are doing 'this' dynamically, do you mean building a
> meta-object?
> Or enum?
> 
> Mårten
> 
>> -----Original Message-----
>> From: Development <development-bounces at qt-project.org> On Behalf Of
>> Phil Thompson via Development
>> Sent: torsdag 3. oktober 2024 13:40
>> To: development at qt-project.org
>> Subject: [Development] Changed enum property behaviour in Qt v6.8
>> 
>> Hi,
>> 
>> Prior to Qt v6.8 it was possible to define a meta-object property with
>> an enum type where the enum was *not* registered with Q_ENUM and the
>> result of QMetaProperty::isEnumType() would be true.
>> 
>> With v6.8 isEnumType() will return false. The change is the extra test
>> on the meta-type in the private QMetaProperty ctor. In this situation
>> the property does not have a valid meta-type and so the extra test
>> fails.
>> 
>> What was the reasoning behind the change?
>> 
>> The best solution would be to ensure the enum was registered with the
>> type system, however I am doing this dynamically (including building 
>> the
>> whole meta-object) and so Q_ENUM is inappropriate and I'm not seeing 
>> an
>> obvious alternative.
>> 
>> Any help would be appreciated.
>> 
>> Phil
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