In case you haven’t noticed, Raymond Chen has joined me in writing about C++/WinRT. He has published a great collection of tips and tricks internally and plans to publish them all publicly as time allows. Here are a few to get you started:
Detecting whether the -opt flag was passed to cppwinrt.exe: Using __has_include
How can I determine in a C++ header file whether C++/CX is enabled? How about C++/WinRT?