podio does no longer build with gcc 11

[tmadlener]

We are planning to remove support for building with gcc11 in v01-03. Tests have been failing to build since #626 and with #620 also building without tests has started to fail with gcc11, as c++20 support is not yet fully there.

This is related removing c++17 support (see #701).

In case you are still using gcc11 for building podio and have requirements that make moving to a newer version impossible or hard, please let us know (e.g. by a comment to this issue).

This is technically a breaking change since we remove a "feature". However, we have decided against bumping the major version of podio for this for now, as the API and the generated code remains unchanged.

We originally planned to remove gcc11 support, but have since realized it is rather straight forward to restore it. Hence, we for now continue supporting gcc 11. We will create a new issue / notification once we actually remove it.

[tmadlener]

@wdconinc @paulgessinger FYI

[wdconinc]

Thanks for the heads-up. Our lowest gcc is 12 so we should be fine for this transition.

[paulgessinger]

We currently still build on stock alma9 and ubuntu2204 which are on gcc11. I don't think we need to keep this much longer so should be ok.

@tmadlener std::format? 😉

[tmadlener]

No, some parts of ranges / views actually: #620 (comment)

For std::format I have just gone to fmtlib directly for now.