Thanks, Paul, Mateusz, Mike for your answers. For anyone interested, there are more comments on this topic on the boost channel on cppslack.
On 27. Sep 2019, at 11:07, Paul A Bristow via Boost
wrote: But an email kept by you transferring copyright from 'anon' to you might be a way of keeping the author anonymous?
Possible, but cumbersome.
That may still leave 'anon' vulnerable if he wants to keep his contribution secret from his employer (who prohibits publication without their authorisation) , for example, but in practice it would be OK.
If it is indeed case that the code was written while anon was under contract to do something else, then this would be a strong reason to not accept the code.
For a PR, I'd be tempted to just put your name on the copyright claim.
The problem is that I started to think seriously about this and now I cannot just stop. Putting my name on the copyright claim leaves me open to be sued by anon for copyright infringement unless there is a proper written contract that legally transfers the copyright of the code to me. Of course we could write down something and I could keep it forever in a drawer, but I don't want to complicate my life with this. I sympathise with Mateusz' view. For the future, I will make sure that potential contributors cannot contribute anonymously. Perhaps I have to rewrite the feature that anon provided from scratch. Let's see. Best regards, Hans