Metaprogrammed header to work safely with MCU registers without any influence to run-time (for Cortex-M3/M4 even more effective than plain C) that as written with C++20 using templates, constexpr ...

is compiled by using the command line CL /YuMYAPP.H PROG.CPP, the compiler doesn't process the three include statements.Instead, it uses precompiled code from MYAPP.pch, which saves the time involved ...