I need some guidance from Boost developers in general. A PR has been issued for Boost PP which only affects Intel C++ 17 on up in Windows. I can ascertain that only this compiler in Windows is affectd by the PR. Needless to say I do not test this personally because it costs a decent amount of money to buy a license. Intel does graciously offer free licenses for Intel C++ on Linux for Boost developers and I have used it to test the compiler under Linux. Also there are no regression tests for Intel C++ on Windows in the 'develop' or 'master' regression test matrices. While the person who issued the PR ascertains that it fixes problems for Boost libraries he uses with Intel C++ 17 on Windows the nature of the PR is drastic enough that it could easily break other libraries if the changes in the PR does not correspond to Intel C++ preprocessing in all cases. So my quandary is what to do about the PR. The PR is at https://github.com/boostorg/preprocessor/pull/9#issuecomment-256741882. It is another one of these cases, like clang targeting VC++, where a compiler implementation on Windows wants to emulate the non-standard VC++ preprocessor but can't quite get it right ( as if emulating a broken preprocessor should ever be right ). Thoughts ? Ideas ? Suggestions ?