Can I use #include "pch.h" instead of #include "stdafx.h" as my precompile header in Visual Studio C++?

Question

This is my first time working with C++ and properly getting into coding. I'm following the C++ tutorials on learncpp.com and I'm using Visual Studio 2017...

In the tutorial they start off with some simple "Hello, world!" code and at top of the code they put #include "stdafx.h" along with #include <iostream>. When I replicate this code myself and try to build it, I get the error:

C1010: unexpected end of file while looking for precompiled header. Did you forget to add #include "pch.h" to your source?

When looking at my solution explorer I noticed that in their tutorial in the header and source files tab they have files called "stdafx.h" and "stdafx.cpp", but for me those files are called "pch.h" and "pch.cpp".

So I then tried renaming the #include "stdafx.h" to #include "pch.h" and the code was built and executed perfectly. So should I just stick with #include "pch.h" for the rest of my code or is this some kind of issue?

Thanks!

Answer 1

The default precompiled headers name was stdafx.h for several years now. Lately, with VS 2017, they changed the default name the project wizard creates to pch.h. I don't know why but they did it.

You can adjust the name of the precompiled header file in the Project Properties under Configuration Properties -> C/C++ -> Precompiled Headers. You can also enable or disable the use of them there. You can even define this on a per file basis. You can even configure multiple different Precompiled Header files in one project.

So for you concrete question: There won't be any kind of issue replacing stdafx.h with pch.h in your tutorial. The tutorial is probably just older and hasn't been updated yet.

Answer 2

Try moving "#include pch.h" to the very top of the file (before any other headers).

Some compilers won't compile content before the pre-compiled header file(s) by default. This setting can be changed though.