In article <2e43a8d1-bb10-4f5a-b10d-25061098c032n at googlegroups.com>, xyzzy1959 at gmail.com (John Reagan) wrote: > Current clang does not fully support C++20 or C++2b > > https://clang.llvm.org/cxx_status.html Ah, that was where I went wrong: I was under the impression it had full c++20. Apologies. John