On 2/20/12 10:47 AM, "ext Thiago Macieira" <thi...@kde.org> wrote:
>> > It's also possible to have different .qml files having slightly >>different >> > imports. You just can't mix major versions, because the backend >>library is >> > completely different. >> >> I would also assume that it's necessary to have separate files for each >> supported version. I can only speculate on how many there would be, but >> my guess would be not too many. So it might not be a problem. If there >> are a lot of them, it would become a maintainance nightmare. > >Indeed, separate files. The point is that you should not have to keep >many >files. Once you're ready to upgrade (and require a new version), you do >it and >don't look back. You don't keep two versions working. Another common case for #ifdefs is configuration management in cross-platform projects. It's not always possible to port a project to a new platform and never look back. :-) In one of our Qt SDK user surveys, we asked how much people use non-Qt APIs in their projects. Only around 20-25% of projects were 100% Qt code, varying a bit between target platforms. Here are the results for one random platform, Mac OS X (N = 287): My application is 100% Qt Code: 20.6 % Small part of my application uses non-Qt APIs: 54.0 % Significant part of my application uses non-Qt APIs: 17.1 % I use Qt for a small part of my application only: 3.8 % I know this data doesn't prove that #ifdefs are required, because maybe some of the non-Qt APIs might be cross-platform, and maybe some of the code that calls non-Qt non-cross-platform APIs can be separated out in platform-specific source files. Anyways, cross-platform Qt C++ projects often benefit from being able to have #ifdefs around some short snippets inside a file. I would expect some sort of conditional evaluation statement would be useful in cross-platform Qt Quick projects too. Cheers, Henry _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
