Daniel Ruoso via SG15 <sg15_at_[hidden]> writes:

> Essentially, the C++ specification needs to be implementable in all
> the places where C++ is currently used, and the specification of
> Importable Headers currently fails that criteria. It is only
> implementable in a subset of environments where C++ is used.

This is a red herring, IMO.

Firstly, there are plenty of "places where C++ is currently used"
where C++11 (let alone C++20) is not implementable. Does that mean
we should "walk back" to C++98?

Secondly, C++20 header units are always implementable by the C++
compiler directly (i.e., the "turn the compiler into a build system"
approach). It may not be desirable or practical, but it is
implementable anywhere, "where C++ is currently used".