following Richard Smith’s talk at CppCon this year where he mentioned that Clangs Module TS implementation,
while still work in progress, can already be used to build stuff, I decided to try it out.
So I compiled Clang 4.0 from svn, create a module interface file ‘myclass.cppm’ and a ‘main.cpp’ to test it.
I’ve gotten it to build successfully by executing
clang++ -std=c++1z -fmodules-ts --precompile -o myclass.pcm myclass.cppm clang++ -std=c++1z -fmodules-ts -fmodule-file=myclass.pcm -o modules_test main.cpp
So far so good. But on the Modules FAQ page  it says:
The binary representation of modules is automatically generated by the compiler on an as-needed basis.
Is this only implemented for Clang’s “C++98 style modules” yet or am I missing a flag I need to pass to clang++
in order for it to precompile my module automatically? Currently neither of
clang++ -std=c++1z -fmodules-ts main.cpp
clang++ -std=c++1z -fmodules-ts myclass.cppm main.cpp