On Sat, Sep 14, 2019, 2:38 PM Jason Merrill via Core <core@lists.isocpp.org> wrote:

This doesn't seem to have been addressed at Cologne. I don't think
any of the changes at Cologne (conditionally trivial, unconstrained
TTP, dropping return-type requirements) require a version bump, does
anyone else?

So I'd stick with the 201811 value.

Jason

Wait, do we even have a __cpp_concepts? We have a __cpp_lib_concepts (... that def needs to be bumped to 201907), but not one for the language. We should add one...

Barry