What are Precompiled Header files?

What are Precompiled Header files?

In computer programming, a precompiled header (PCH) is a (C or C++) header file that is compiled into an intermediate form that is faster to process for the compiler.

How do I add a Precompiled Header?

The compiler options for precompiled headers are /Y. In the project property pages, the options are located under Configuration Properties > C/C++ > Precompiled Headers. You can choose to not use precompiled headers, and you can specify the header file name and the name and path of the output file.

How do I turn off Precompiled Headers in Visual C++?

To turn off precompiled headers Select the Configuration properties > C/C++ > Precompiled Headers property page. In the property list, select the drop-down for the Precompiled Header property, and then choose Not Using Precompiled Headers. Choose OK to save your changes.

Are Precompiled Headers worth it?

There are some really large projects out there where precompiled headers do make a huge difference. But if using them makes you life miserable for some reason or another (i.e. portability) and your project is not incredibly large.. I’d say skip them. The only obvious benefit is a slight decrease in compilation time.

Do not use precompiled headers?

Select your project, use the “Project -> Properties” menu and go to the “Configuration Properties -> C/C++ -> Precompiled Headers” section, then change the “Precompiled Header” setting to “Not Using Precompiled Headers” option.

What is Stdafx H used for?

stdafx. h is basically used in Microsoft Visual Studio to let the compiler know that the files are once compiled and no need to compile it from scratch.

When should I use Stdafx H?

What is SDKDDKVer?

SDKDDKVer. h is the header file that actually defines the #defines that represent each version of Windows, IE, etc.

Where do I put ” create precompiled header ” in stdafx.cpp?

You put “create precompiled header” only for stdafx.cpp. Then “use precompiled header” for all of the other “.cpp” files. Finally, have include “stdafx.h” at the start of each “.cpp” file (not usually in the header files.

What is the use of stdafx.h in Visual Studio?

Use of “stdafx.h”. By definition “Stdafx.h” is a precompiled header. Precompiled the word implies that this header file is precompiled (once compiled no need to compile it again). Precompiled Header stdafx.h is basically used in Microsoft Visual Studio to let the compiler know the files that are once compiled and no need to compile it from scratch.

How to include the stdafx.h from the root directory?

Write #include “stdafx.h” as first line of all source files in your subdirectories, instead of including the top-level file there. This way, all your code files use the same precompiled header file, and there is no other complicated setup to do. It’s interesting that the trick that I use isn’t in the answers:

When to add a precompiled header file in Visual Studio?

When you create a new project in Visual Studio, a precompiled header file named pch.h is added to the project. (In Visual Studio 2017 and earlier, the file was called stdafx.h.) The purpose of the file is to speed up the build process. Any stable header files, for example Standard Library headers such as , should be included here.