Header File

In general, each .cc should has an associated .h


In order to prevent multiple inclusion, should have #ifndef #define #endif. <PROJECT>_<PATH>_<FILE>_H_

Forward Declarations

Not understanding


Define functions inline only when they are small, say, 10 lines or fewer. recursive functions: not inline virtual function: inline

Review for inline

Names and Order of Includes

File should be listed as descendants of the project's source directory For example, google-awesome-project/src/base/logging.h should be included as:

#include "base/logging.h"

Do not use . or ..

In dir/foo.cc, you want implement dir/foo.h The include order is:

  • dir/foo.h
  • A blank line
  • C system file
  • C++ system file
  • A blank line
  • Other libraries .h files
  • Your project .h files

However, any includes present in the related header do not need to be included again in the related cc (i.e., foo.cc can rely on foo.h's includes).


Do not use using-directives (e.g. using namespace foo).

inline namespace

In the outer namesapce, can directly access methods/variable without using scope resolution ::