Naming Include Guards

Question

How are C++ include guards typically named? I tend to see this a lot:

#ifndef FOO_H
#define FOO_H

// ...

#endif

However, I don\'t think

Answer 1

Look at the code that #include's your header.

If it is something like:

#include "mylib/myheader.h"

mylib/myheader.h is already a unique name. Just capitalize and replace / and . with _

#define MYLIB_MYHEADER_H

If you have two headers on your include path with the same name relative to the include path, you already have a collision at that level.