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

Taken directly from google's style guide:

All header files should have #define guards to prevent multiple inclusion. The format of the symbol name should be ___H_. To guarantee uniqueness, they should be based on the full path in a project's source tree. For example, the file foo/src/bar/baz.h in project foo should have the following guard:

 #ifndef FOO_BAR_BAZ_H_
 #define FOO_BAR_BAZ_H_
 ...
 #endif  // FOO_BAR_BAZ_H_

I use this style in my own projects.