Bump c++ version to 20

[Cropi]

Currently, the CI is failing because it's not able to parse the new [[ unlikely ]] attribute. I am not aware of any other new features the project uses but it might use in the future. We can either remove the attribute or switch to c++20.

Considering that c++20 has been out for a while and compilers already support it, I think it's safe to do.
More info: https://en.cppreference.com/w/cpp/20

[Cropi]

Hello @hartwork,
You as the main contributor to our CI, do you have an opinion on this topic?

• switch to c++20 and fix the CI by using the latest OS or
• remove c++20 features and use the current setup

Thank you in advance.

[hartwork]

@Cropi thanks for the notification. C++20 is younger than 5 years and so requiring C++20 for a software that (1) can easily do without it and (2) is crucial to non-bleeding-edge enterprise I would like to clearly vote against requiring C++20. If you want to make that move, in my view it first needs a list of must-support systems and checking their versions of GCC and Clang and checking the C++20 support of those compilers. Questions like "what is the oldest release of RHEL, Debian, SUSE, Ubuntu that we need to support?" It takes work and before that work the risk is too high in my book.

On a side note I find it concerning that pull request #600 was merged to master despite failing CI. Getting red CI fixed should be everyone's first priority before merging anything else.

What do you think?

[hartwork]

@Cropi I have fixes for all issues with CI now in pull request #628. I am looking forward to your review 🙏

[Cropi]

@Cropi thanks for the notification. C++20 is younger than 5 years and so requiring C++20 for a software that (1) can easily do without it and (2) is crucial to non-bleeding-edge enterprise I would like to clearly vote against requiring C++20. If you want to make that move, in my view it first needs a list of must-support systems and checking their versions of GCC and Clang and checking the C++20 support of those compilers. Questions like "what is the oldest release of RHEL, Debian, SUSE, Ubuntu that we need to support?" It takes work and before that work the risk is too high in my book.

Yes, I fully agree here. It might be an overkill to switch to a newer version when there are no big features depending on it. Thanks for the quick reaction.

On a side note I find it concerning that pull request #600 was merged to master despite failing CI. Getting red CI fixed should be everyone's first priority before merging anything else.

What do you think?