Google C++ Style Quick Reference

A concise summary of essential Google C++ style guidelines to elevate your code quality.

https://google.github.io/styleguide/cppguide.html

1. Naming Conventions

Type	Convention	Example
Namespaces	snake_case	namespace image_processing
Class/Struct/Enum/Type Names	CamelCase	class AudioEncoder
Public Functions	CamelCase	void ComputeValue()
Private/Protected Functions	CamelCase (same as public)	void UpdateInternalState()
Local Variables	snake_case	int local_count;
Public Member Variables (if used)	snake_case	int frame_count;
Private/Protected Member Variables	snake_case_ (with trailing underscore)	int buffer_size_;
Static Member Variables	snake_case_ (with trailing underscore)	static int instance_count_;
Constants (constexpr, const)	kCamelCase	const int kMaxWidth = 800;
Macros	ALL_CAPS_WITH_UNDERSCORES	#define BUFFER_SIZE 256
Enumerators (enum values)	kCamelCase	enum Color { kRed, kGreen, kBlue };
Template Parameters	CamelCase	template <typename InputIterator>
Files	snake_case.h / snake_case.cc	audio_encoder.h, audio_encoder.cc

2. Formatting

1. Only use spaces(no tab). Use 2 spaces at a time.
2. Maximum of 80 characters for each line.
3. Pointers and references: int* p and int& r.

Formatting could be easily resolved using clang-format. Create a .clang-format file in your project’s root directory.

BasedOnStyle: Google
IndentWidth: 2
ColumnLimit: 80

And run the following command line to apply the format.

clang-format -i file1.cpp

3. Include Files

1. Orders: Related header -> C system headers -> C++ standard library headers -> other libraries’ headers -> your project’s headers.
2. All project’s header files need to be listed as descendants of the project’s source directory. No . or ...

#include "example_encoder.h"       // Related header

#include <sys/types.h>             // C system headers
#include <unistd.h>

#include <algorithm>               // C++ standard library headers
#include <vector>

#include "third_party/libx/libx.h" // Other libraries' headers
#include "third_party/liby/liby.h"

#include "media/base/audio_frame.h" // Your project's headers
#include "media/base/buffer_pool.h"

4. Classes and Structs

1. Use a struct only for passive objects that carry data; everything else is a class.
2. Explicitly declare constructors as explicit if they take a single argument.

5. Const Correctness

Mark member functions as const if they do not modify object state.

6. Lambda Expressions

Prefer explicit capture over [=] or [&] to avoid accidental capture.

7. Defining Functions in Headers

Functions defined at the point of declaration are inline by default.

Based on the guide, there are PROs and CONs doing that. The rule is: the definition has 10 lines or fewer.

Adding More