How to check programmatic by preprocessor directive whether a pre-compiled header is required in Visual C++?

Question

Sometimes it would be useful to know whether the compiler requires a pre-compiled header or not, and how the header file is called. My goal is to add some preprocessor directives like this:

#ifdef REQUIRES_PRECOMPILED_HEADER
#include PRECOMPILEDHEADER_FILE
#endif

So my question is: Are there predefined variables like REQUIRES_PRECOMPILED_HEADER and PRECOMPILEDHEADER_FILE?

If there is, it will be listed [here](http://msdn.microsoft.com/en-us/library/b0084kay.aspx). — ildjarn, Jun 19 '12 at 00:14
Are you sure that this is the complete list of predefined variables? If so the answer would be 'No'. But as far as I know Microsofts documentation is sometimes incomplete or out of date. — Christoph Meißner, Jun 19 '12 at 00:20
The answer is indeed no. Convention is stdafx.h. But create your own project, make it a static lib project. — Hans Passant, Jun 19 '12 at 00:22
-1 "Since Visual C++ requires the pre-compiled header to be included into all source files" is wrong — Cheers and hth. - Alf, Jun 19 '12 at 00:25
So correct me, but don't just say "is wrong". I just answer at my best knowledge. — Christoph Meißner, Jun 19 '12 at 09:07

score 1 · Answer 1 · answered Jun 19 '12 at 00:28

It's not your task to support others' use of precompiled headers. It's up to them to add your header to their precompiled header, or not. You just create trouble by trying to do it for them.

So, problem solved: don't do that.

It's unnecessary and it creates trouble.

score 1 · Accepted Answer · answered Jun 19 '12 at 01:10

1

Well presumably your source files will not need any of the headers included in the precompiled header. So, if you are trying to include your source files in a project where other source files do use precompiled headers, just make sure precompiled headers are turned off for yours.

Just select the properties for your source files, and under "Precompiled Header" select "Not Using Precompiled Headers".

answered Jun 19 '12 at 01:10

zdan

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Okay that solves the problem in the easy way. (I usually avoid using pre-compiled headers, so I'm not really used to them. Thanks for that hint.) – Christoph Meißner Jun 19 '12 at 09:18

How to check programmatic by preprocessor directive whether a pre-compiled header is required in Visual C++?

2 Answers2