I am the prinicipal developer of zapcc. We have added a FAQ http://www.zapcc.com/faq/ http://www.zapcc.com/faq/ and more tech details in the cfe-dev mailing l

I am the prinicipal developer of zapcc. We have added a FAQ http://www.zapcc.com/faq/ http://www.zapcc.com/faq/ and more tech details in the cfe-dev mailing list http://lists.cs.uiuc.edu/pipermail/cfe-dev/2015-May/043174.html http://lists.cs.uiuc.edu/pipermail/cfe-dev/2015-May/043174.h... To the point, zapcc will not reprocess foo.h. This is a limitation. However, zapcc does deal with templates instantiations and such correctly and fast, such as boost various libraries, Eigen and LLVM source code.