Are modules already kind of unofficially supported, or can they be enabled ? On what platforms ? I'm trying to make a C++ game with fat libraries like Ogre3D a

Are modules already kind of unofficially supported, or can they be enabled ? On what platforms ? I'm trying to make a C++ game with fat libraries like Ogre3D and bullet3D, often on a laptop, and that would really be fantastic to not wait 10s or more each time I edit a header. I've seen a presentation, basically modules would decrease compile time from M x N to M + N.