This link must give you some clue. Purpose of stdafx.h The lines defined before the #include “stdafx.h” are ignored by the compiler. So if you want to actually include those files then you need to include them after the #include “stdafx.h”. Hope it is clear.
stdafx.h is a file, generated by Microsoft Visual Studio IDE wizards, that describes both standard system and project specific include files that are used frequently but hardly ever change. Compatible compilers (for example, Visual C++ 6.0 and newer) will pre-compile this file to reduce overall compile times. Visual C++ will not compile anything before the … Read more
All C++ compilers have one serious performance problem to deal with. Compiling C++ code is a long, slow process. Compiling headers included on top of C++ files is a very long, slow process. Compiling the huge header structures that form part of Windows API and other large API libraries is a very, very long, slow … Read more