[Development] Supported compilers for Qt 6

[Lars Knoll]

Hi,

As mentioned in my blog, it would be good to move forward with the C++ version we use for Qt 6 and ideally move it to C++17. That implies that we need to drop some older compilers for Qt 6. As 5.15 is going to be an LTS release, I don’t think this is going to be a huge problem.

Here’s the baseline I would like to propose:

VC++ 2019
GCC 8
Clang 6
Apple Clang 10.0

This limits us to compilers that are not more than 2 years old. I’d propose that with Qt 6, we can then use the core language features that are supported by all of those compilers (including C++20 features if supported by them all).

We should also be able to use the common subset of library features supported by the standard libraries of those compilers in our implementation. In our APIs, I would still like to continue with our current approach of discussing and white-listing specific APIs on the development mailing list.

Cheers,
Lars