Iain Sandoe via SG15 <sg15_at_[hidden]> writes:

> Suppose we chose to require that they start with “header-unit;”?

Overall, I agree with the relies so far: the point of header units
is to be able to import "reasonably modular" headers without any
modification.

FYI, this section describes how we handle importable headers in build2:

https://build2.org/blog/build2-cxx20-modules-gcc.xhtml#include-translation