On Sun, 23 Aug 2020 at 22:34, Zach Laine via Boost
On Sun, Aug 23, 2020 at 1:35 PM Mike via Boost
wrote: Could you maybe point me to the relevant location in the standard? A quick test with compiler explorer (https://godbolt.org/z/EP18s1) turns not up any errors, but of course I doubt any compiler implements modules completely to spec yet.
No, because it looks like that changed! The rule I had in my head is from a previous version of the feature. Sorry for the noise.
It is, however, worth noting that if you have, say, 16 different possible preprocessor outputs, you can just ship one header with the preprocessor conditionals that with their different values give you 16 programs, but you need to ship 16 modules to get the same result in a modular world.