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Now, I realized that I need a precompiled header for my project. However, at the beginning, I created my project as an empty project which doesn't have a stdfx.h header file. So, this is what I did:
- I created a header file name stdfx.h
- In that file, I included some libraries.
- I went to the project Property Pages -> C/C++ -> Precompiled header -> set the PRECOMILED HEADER option to Use (/Yu).
- Finally, I included stdfx.h in every cpp file.

It works. However, I am wondering if the stdfx.h file that I created myself works like the one that is automatically created by Visual Studio? I mean is it really a precompiled header which will save time when compiling or just a normal header file?

Stoatman
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2 Answers2

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It's normally named stdafx.h, but it really doesn't matter. You can name your precompiled header whatever you want.

You are missing one final step.

You also need to create a stdafx.cpp. This is an empty file that only has a #include "stdafx.h" line.

For this particular file, right click on it in the Solution Explorer and select Properties. This will bring up a Properties page with settings specific to this source file (in inherits your project settings by default). For this particular file, select /Yc as the compiler option instead of /Yu for the Precompiled setting. If you don't do this, you may not observe the build speed improvements of precompiled headers.

When Visual Studio builds, it will build your stdafx.cpp file first. And along with that, it will build the .pch file that the other source files will pick up.

And while I'm here. The things to include in the precompiled header file are all the system and C/C++ runtime header files. (e.g. <windows.h>, <stdio.h>, <string>, <map>, etc...). You'll get the most gains by including all these files - since they never change from build to build.

selbie
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You definitely can make stdfx.h by yourself or other precompiled header file (name is not really important). But you should follow some rules described in MSDN.

You can read more about precompiled headers in the Documentation

VolAnd
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