cpp_style_guide

CPP STYLE GUIDE
---------------

GENERAL
-------

Use 2-space indentation.

Don't use trailing braces everywhere (if, else, functions,
structures, typedefs, class definitions, etc.)

  if( x )
    foo

Connect opening parenthesis to control statements (if, while, switch,
for, etc.) and pad parenthesized expressions with spaces

  if( x ) {
  }

Instead of
  if (x) {
  }

Function names are lower case:

  void foo();

Use snake_case for multi-word function names:

  void do_this();

Instead of

  void dontDoThis();

Class names start upper case:

  class Foo {
  }

Function arguments and local variables start lower case:

  float x;

Member variables start with a '_' followed by a lower case character:

  class Foo {
    public:
      int _bar;
  }


Use camel-case for multi-word variables:

  int myVariable;

Typedef and names follow the same convention as
function names, however they always end with "_t":

  struct config_t {
    int x;
    int z;
  };

Note that struct variables have the same naming convention as function
arguments and local variables;

Enum declarations are strongly typed and have all upper case names and
constants. Multi-word names are in upper snake case:

  enum class MY_ENUM {
    A,
    B,
    C_BAR_BAZ
  };

Names of recursive functions end with "_r"

  void visit_node_r( int node );

Defined names use all upper case characters. Multiple words are
separated with an underscore.

  #define SIDE_FRONT 0

Use ‘const’ as much as possible.
Use:
  const int *p; // pointer to const int
  int * const p; // const pointer to int
  const int * const p; // const pointer to const int

Don’t use:

  int const *p;

CLASSES
-------

Each class should be a separate source file unless it makes sense
to group several smaller classes.

The file name should be the same name of the class and the
companion header file uses prefix ".h" and not ".hpp"; for example,
class Foo will have files:

  Foo.cpp
  Foo.h

Ordering of class variables and methods should be as follows:

  1. list of friend classes
  2. public variables
  3. public methods
  4. protected variables
  5. protected methods
  6. private variables
  7. private methods

This allows the public interface to be easily found at the beginning
of the class.

Always make class methods ‘const’ when they do not modify any class
variables.



HEADER FILES
------------

Header begin with a #ifndef name composed of the project
name followed by the fully-qualified relative path of the file
from the include directory and ended by the character H. Names
should be in lower snake case. For example, for a project named
Juniper having an include directory structure like

  include/
    juniper/
      juniper.h
      sockets/
        socket.h

The #ifndef names would be

    juniper/juniper.h        -> juniper_juniper_juniper_H
    juniper/sockets/socket.h -> juniper_sockets_socket_H

It is fine to mix definition and implementation in header files
for Rcpp projects.