There is a proposal to add modules to the C++ standard.

A Module System for C++ (Revision 3)

This builds on a much earlier proposal in 2006 by Daveed Vandevoorde

Modules in C++

Microsoft has done an early implementation in Visual Studio 2015 Update 1 (because the authors of the new module proposal package work at Microsoft)

C++ Modules in VS 2015 Update 1

I’m not terribly excited about some parts of their proposal and implementation. But I should play with it. So. I will play with it. Update to come.

Reference

C++ Modules - why were they removed from C++0x? Will they be back later on?

State of C++ Evolution (Post San Francisco 2008)

Clang 3.9 - Modules

A module system for the C family

CppCon 2015: Gabriel Dos Reis “Large Scale C++ with Modules: What You Should Know” and slides

Modules and video

Getting Started with Modules in C++