Due to various force-majeure travel reasons, I personally managed to miss the weekend before the mailing deadline and the deadline itself, so it was brought to my attention a tad too late that nobody wrote this proposal paper. So here goes.
The proposal is to merge the Concepts TS Working Draft into the C++20 Working Draft as is, and fix remaining issues, including design issues, before the publication of C++20.
According to the Concepts TS Editor's report, the current TS has been rebased to apply to the C++20 working draft. The TS draft is in the pre-Toronto mailing:
Working Draft, C++ extensions for Concepts
I am well aware of that, but I'm boldly suggesting that we take a brave step and send a message to the C++ community that we are serious about having Concepts in C++20. In fact, a leap so brave that we merge the current wording in and all commit to finishing it up design-wise, wording-wise and otherwise before C++20 goes out, without missing its schedule.
I'm also well aware that we don't usually merge new wording which has known issues (except when we do, but that happens much more rarely for Core than Library). Perhaps this facility is significant enough to make an exception.