On Wed, Mar 06, 2019 at 17:42:37 -0500, Steve Downey wrote:
> You can assume it succeeds, but the compiler can't know what macros will be
> exported from a header unit.

There's `#export` (and `#export *` is implicit somewhere, but I don't
think it's for explicit module setups), is there not?

> However, it's also ill-formed to have a module
> translated in two different ways in a project,

Well, within a *program*. Building debug and release variants of the
same code is OK as long as they don't end up linked together.

> or to depend on an #include
> being different than a header module in the same build.

Do you have an example of this? It isn't exactly clear in my mind what
this means.

> The question is if
> it's detectable.

The BMI formats of GCC and Clang hold information about this kind of
stuff. If they don't have all of it, more sanity checking information
can be added to the files.

--Ben