c++-modules

I'm trying to use C++ modules TS with clang. I've created two files: // foo.cppm export module foo; export void test() { } and // bar.cpp import foo; int main() { test(); return 0; } I compile foo.cppm with this command clang++ --std=c++17 -fmodules-ts --precompile foo.cppm -o foo.pcm It compiles without an error and creates a foo.pcm file, but when i try to compile a binary with this command: clang++ --std=c++17 -fmodules-ts -fprebuilt-module-path=. -fmodule-file=foo.pcm bar.cpp it prints an error: /tmp/bar-f69a1f.o: In function `main': bar.cpp:(.text+0x10): undefined reference to `test()' I

There are already two compilers that support C++ modules: Clang: http://clang.llvm.org/docs/Modules.html MS VS 2015: http://blogs.msdn.com/b/vcblog/archive/2015/12/03/c-modules-in-vs-2015-update-1.aspx When starting a new project now, what should I pay attention to in order to be able to adopt the modules feature when it is eventually released in my compiler? Is it possible to use modules and still maintain compatibility with older compilers that do not support it? There are already two compilers that support C++ modules clang: http://clang.llvm.org/docs/Modules.html MS VS 2015: http://blogs

Modules are an alternative to #includes. Clang has a complete implementation for C++ . How would I go about if I wanted to use modules using Clang now? Using import std.io; in a C++ source file does not work (compile) yet, as the specification for modules (which includes syntax) isn't final. The Clang documentation states that, when passing the -fmodules flag, #includes will be rewritten to their appropriate imports. However, checking the preprocessor suggests otherwise (test.cpp only contains #include <stdio.h> and an empty main): $ clang++-3.5 -fmodules -E test.cpp -o test $ grep " printf "