I think i have solved your problem for writing GUI apps for Windows

[trcrsired]

I have just read your blog post:
https://tulach.cc/writing-gui-apps-for-windows-is-painful/

We have figured out a way to use clang directly. Here is an example:
https://github.com/trcrsired/winrt-toys/blob/main/0003.hellogeo/main.cpp

[trcrsired]

https://github.com/trcrsired/windows-msvc-sysroot