Hi, you've explicitly excluded ABI from the discussion ("Let's focus first on the C++ language, because the ABI discussion is irrelevant if we don't do this"), and ignoring ABI, I do indeed see mostly two issues:
1. Ensuring that CI gives us enough test coverage, which I suspect might be solvable by configuring Qt to build examples and tests by default still with 17. 2. Compile times, which I see getting worse when switching to 20, and not improving until we can use "import std". And that's not probably not viable even in C++23 builds unless mixing and matching of import and include of SLT headers works reliably. I don't consider compiles slower a blocker though, especially if compiling in 17 mode is still possible. However, if it comes to ABI, I'm not convinced that we have a solution. As long as e.g. libstdc++ declares its support experimental, are we really willing to export C++20 symbols from Qt? If not, do we have strategy to prevent this from happening? Kind regards, Fabian ________________________________________ Von: Development <development-boun...@qt-project.org> im Auftrag von Thiago Macieira <thiago.macie...@intel.com> Gesendet: Montag, 28. Oktober 2024 16:29 An: development@qt-project.org Betreff: Re: [Development] Switching Qt default builds to C++20 where supported On Monday 28 October 2024 00:59:25 Pacific Daylight Time Vladimir Minenko via Development wrote: > Hi Thiago, > > I would not take the silence as a sign of consent. I rather have the > impression that there is no sufficient interest in this at the moment. > Despite this, there are quite a few urgent improvements required on the CI. > I greatly doubt it will be possible to have additional configurations for > any of the permutations of conditions you might need. Lazy consensus is part of our governance. If no one speaks up with arguments against, it implies no one has arguments against of sufficient interest to them to voice in the first place. Lack of interest and apathy imply people don't care enough one way or the other. I am not asking for additional configurations in the CI. -- Thiago Macieira - thiago.macieira (AT) intel.com Principal Engineer - Intel DCAI Platform & System Engineering -- Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development