Thread: How do you order your include statement

To All:

I learned C when it was K&R C and I ordered by headers from specific to the general.
I am still working on learning C++ in my free time.

Example in mymodule.c

Code:

#include "mymodule.h"
#include "mylibrary.h"
#include <3rdpartylibrary.h>
#include <stdio.h>

But, an C++ project I use/submit patches normally use general to the specific.

Example in thisclassmodule.cpp

Code:

#include <iostream>
#include <3rdpartyclass.h>
#include "myclass.h"
#include "thisclassmodule.h"

Is this just an C++ thing?
Is it recommend to use either order in C?

Tim S.

Originally Posted by claudiu

I tend to include the specific ones on top as well. An include is just a copy paste of that file so it doesn't really matter I guess as long as you have guards to avoid conflicts.

I usually include in this order:
1. C++ std headers (if applicable)
2. standard C headers
3. Blank line
4. Header file related to this source file (if applicable)
5. Other header files

But whatever you prefer...

I don't pay too much attention to the order, I just put filenames wrapped in double-quotes near the bottom.

Originally Posted by stahta01

To All:
I learned C when it was K&R C and I ordered by headers from specific to the general.
I am still working on learning C++ in my free time.

Interesting answers so far....

I tend to look at what needs something that's in something else (dependencies)

For example, if I declare a project header that uses typedefs from windows, if I put it before the <windows.h> header I'm going to get a gazillion errors. So for me it's about having things in place before they're needed... same way I order my functions above Main or WinMain...

I suppose this could be called "general to specific" but it's really about "planted before harvested"...

Originally Posted by Salem

I tend to go for this order - start with the broadest standard first, with increasing levels of specialisation.

ISO header files (stdio.h and the like)
POSIX headers (if applicable)
OS headers
3rd party library headers
Local library headers
Local module headers

I use this with exception that sys/ headers are on top.