Thing is (correct.me if Im wrong), that if you use modules, all of your code need to use modules (e.g. you cant have mixed #include <vector> and import <vector>; in your project). Which rules out a lot of 3rd party code you might want to depend on.
you wrong
You can simply use modules with includes.
If you will #include vector inside your purview then you will just get a copy of the vector in each translation unit. Not good, but works. On the other hand. If you include a vector inside the global module fragment, then the number of definitions will be actually 1, even if you include it twice in different modules.
Well, the standard says you can, but it doesn't actually work in practice in msvc, which is the only compiler that's supported modules for over a year.
