Support for C++2a
The CXX_STANDARD
property currently only supports C++11, C++14 and C++17. Work on C++2a, which will very likely be released as C++20, is well underway and already has multiple useful features.
All three major compilers support switches for it:
Related to #17146 and #16608. The concensus in #17146 seems to be to add support for new CXX_STANDARD
values.